Liquid crystal display device and method of manufacturing the same

ABSTRACT

In a liquid crystal display device in which a plurality of liquid crystal layers are stacked on a substrate, a method for bonding a film for sealing liquid crystal to supporting members is improved and the fabrication cost is thereby reduced, in order to provide a reflective type liquid crystal display device that achieves a bright display image and causes no parallax problem, and to provide a reducing method of the device. The liquid crystal display device comprises a substrate, a resin film, a multiplicity of columnar supporting members, an adhesive layer, and a liquid crystal layer. The substrate comprises a pixel electrode and a driving element connected to the pixel electrode, both formed on the upper surface of the substrate. The resin film comprises a common electrode provided on the upper surface of the film, and is disposed upwardly with respect to the substrate. The supporting members are provided on the substrate so as to support the resin film. The adhesive layer is provided between each of the supporting members and the resin film so as to bond the resin film to each of the supporting members. The liquid crystal layer is produced by filling liquid crystal between the substrate and the resin film. The adhesive layer is composed of a thermoplastic material, and characterized in that a bonding state of the resin film and the supporting members is realized by making the adhesive layer have a thermoplastic characteristic.

TECHNICAL FIELD

The present invention relates to a liquid crystal display device and amethod for fabricating the same. More specifically, the presentinvention relates to a liquid crystal display device which has aplurality of liquid crystal layers stacked on a substrate and providesbright color images even when it is a reflective type, and to a methodfor fabricating the same.

BACKGROUND OF THE INVENTION First Prior Art

Widely used conventional liquid crystal display devices display imagesby combining twisted nematic liquid crystal and a polarizing plate so asto control penetrating light for each pixel. Conventional liquid crystaldisplay devices for displaying color images have micro color filterscorresponding to adjacent three pixels and penetrating red, green, andblue lights by the additive process.

However, in such a conventional liquid crystal display device a largeamount of light absorption in the polarizing plate and the micro colorfilters causes the transmissivity in the entire liquid crystal displaydevice to be about 10% or less, making it difficult to provide brightdisplay images. In particular, in a reflective type liquid crystaldisplay device which utilizes external light, the display is likely tobe so dark as to make the colors unrecognizable.

Japanese Laid-open Patent Applications No. 61-238024 and No. 3-238424show liquid crystal display devices which display bright color imageseven when they are used as reflective type because of a guest host modefor controlling the absorption and penetration of light for each colorby using dichroic dyes. These liquid crystal display devices comprise aplurality of stacked panels each having a liquid crystal layercontaining a dichroic dye different from each other. To be morespecific, the three liquid crystal panels each comprise liquid crystalcontaining dichroic dyes of cyan, magenta, or yellow and sealed intobetween a pair of glass substrates. When all the panels absorb light,images are displayed in black; when all the panels penetrate light,images are displayed in white; and when one or two panels absorb light,images are displayed in colors. Not having a color filter or apolarizing plate for absorbing light, the display device with the guesthost mode provides bright and clear color display and is suitable for areflective type liquid crystal display device.

However, the liquid crystal display device comprising a plurality ofstacked panels each having a pair of glass substrates has the followingdrawback. When the pixels are small, the thickness of the glasssubstrates composing each panel becomes relatively large as comparedwith the size of the pixels, and as a result, the parallax becomes soinfluential as to cause unevenness in color when display images are seenin a diagonal direction.

In order to solve the unevenness in color due to the parallax, aso-called polymer diffusion type liquid crystal display device has beenproposed as in Japanese Laid-open Patent Application No. 6-337643. FIG.79 shows the polymer diffusion type liquid crystal display device, whichcomprises a substrate 1291 and liquid crystal layers 1295-1297 stackedthereonto by solidifying a resist material or polymeric material 1298 inwhich a guest host liquid crystal 1299 is dispersedly held. The displaydevice further comprises driving electrodes 1292-1294 which correspondto the liquid crystal layers 1295-1297, respectively and are connectedwith corresponding driving elements formed on the substrate 1291. Such astructure requiring no glass substrate between adjacent ones of theliquid crystal layers 1295-1297 realizes a liquid crystal display devicewith a guest host mode which is freed of unevenness in color resultingfrom parallax.

However, in the polymer diffusion type liquid crystal display device,the guest host liquid crystal 1299 is dispersedly held in the resistmaterial or polymeric material 1298, so that the resist material orpolymeric material 1298 makes up a large proportion of the liquidcrystal layers 1295-1297 (the guest host liquid crystal 1299 makes up asmall proportion of the liquid crystal layers 1295-1297). This causes aproblem that a substantial open area ratio becomes small, making itdifficult to have a high contrast ratio.

Prior to the liquid crystal display device of the present invention, theinventors of the present invention have proposed a liquid crystaldisplay device in Japanese Laid-open Patent Application No. 9-127057which is shown in FIG. 80. The liquid crystal display device comprises asubstrate 1101, film-like sealing plates 1113-1115 stacked on thesubstrate 1101 while being supported by supporting members (spacers)1108-1110, and liquid crystals 1125-1127 sealed into between thesubstrate 1101 and the sealing plate 1113, between the sealing plates1113-1114, and between the sealing plates 1114-1115, respectively. Theuse of the film-like sealing plates 1113-1115 supported by thesupporting members 1108-1110 solves the unevenness in color due toparallax which is caused when glass substrates are used. Furthermore,the polymeric material which is used to hold liquid crystal in theabove-mentioned polymer diffusion type liquid crystal display device isnot required, so that the liquid crystal makes up a large proportion ofthe liquid crystal layers 1125-1127 disposed between adjacent ones ofthe sealing plates 1113-1115. This makes it possible to increase asubstantial open area ratio, thereby increasing the contrast ratio.

The supporting members 1108-1110 can be formed by applying aphotosensitive resin onto each of the substrate 1101 and the sealingplates 1113 and 1114 and polymerizing and hardening parts of thephotosensitive resin by mask exposure, where the supporting members1108-1110 are formed, and then eliminating the remaining part of thephotosensitive resin by development.

However, in the liquid crystal display device comprising the stackedfilm-like sealing plates 1113-1115, each of the supporting members1108-1110 must be formed exactly in the same position as each other inorder to securely support the sealing plates 1113-1115. For example,when the supporting members 1108 are formed in different positions fromthe supporting members 1109 as shown in FIG. 81(a) due to low precisionin positioning, these sealing plates are deformed as shown in FIG. 81(b)by the pressure of bonding the sealing plate 1114 to the substrate 1101.When the positional deviation between the supporting members 1108 and1109 is large, the supporting member 1109 of a second display layer 1122encroaches on a first display layer 1117 as shown in FIG. 81(c) so as todestroy the first and second display layers 1117 and 1118. In order toavoid this problem, the formation of the supporting members 1108-1110 bymask exposure requires mask alignment of high precision.

Since the supporting members 1108 and 1109 are in the region where thelight transmissivity is not controlled, it is preferable to make thearea for the supporting members 1108-1110 in pixels as small as possiblein order to have a larger open area ratio. This requires higherprecision in mask alignment. To be more specific, in the case where thesupporting members 1109 are square pillars of 7 μm×7 μm, the positionaldeviation of 3 μm or more between the supporting members 1108 and 1109damages the first display layer 1117 and other components as describedabove. Therefore, mask alignment must be performed so as to make thepositional deviation less than 3 μm.

As a result, the device has a problem that the provision of a precisionmasking process leads to an increase in the production cost.

Second Prior Art

The inventors of the present invention previously filed JapaneseLaid-open Patent Application No. 9-127057, which is about a liquidcrystal display device successfully overcoming the problem of the liquidcrystal display device shown in FIG. 79. The invention according to theapplication is the foundation of the present invention and comprises aliquid crystal layer filled with liquid crystal and disposed between asubstrate and a sealing film, and supporting members for supporting thesealing film. The liquid crystal display device makes it possible thatliquid crystal makes up a larger proportion of the liquid crystal layerand the effective open area ratio is increased as compared withconventional devices, so as to improve the contrast ratio.

Although the invention of the application (Japanese Laid-open PatentApplication No. 9-127057) has overcome the problems of the conventionaldevice shown in FIG. 79, it has new problems described below. In orderto solve the new problems, the inventors of the present invention haveachieved the present invention after conducting research and developmentbased on the invention of the application (Japanese Laid-open PatentApplication No. 9-127057). Thus, the present invention has overcome theproblems of the conventional device shown in FIG. 79 and further solvedthe new problems of the invention on which the present invention isbased.

The structure and problems of the invention on which the presentinvention is based will be described. In the invention, the sealing filmis formed onto the supporting members by either method (1) or method(2).

(1) The sealing film is formed on the surface of a plate-like member andtransferred onto the supporting members formed on the substrate. Afterthis, the plate-like member is removed.

(2) A solid film having volatility is formed onto the substrate havingthe supporting members thereon, and the sealing film is stacked onto thesolid film. After this, the solid film is vaporized so as to form a gapbetween the substrate and the sealing film.

In method (1), when the removal of the sealing film is not smooth, thetransfer becomes unsuccessful, which leads to a decrease in the yield.The cause of this is that when the adhesion between the supportingmembers and the transferred film is locally small as compared with theforce to remove the transferred film from the plate-like member, thesealing film cannot be successfully transferred. In a pixel part, it ispreferable to make the area for the supporting members as small aspossible in order to increase the open area ratio; however, when thearea for the supporting members is small, the bonding area between thesupporting members and the transferred film also becomes small, so thatthe small bonding area is exclusively subjected to a pressure forremoving the film, which makes both the transfer and the removalunsuccessful.

In method (2), when the solid film is formed on the substrate having thesupporting members thereon, the solid film sometimes thinly covers thesupporting members, thereby blocking the bonding between the supportingmembers and the sealing film and making the sealing film unstable. Thisleads to a decrease in the yield.

In these two cases, increasing the area for the supporting members inthe pixel plane may facilitate the bonding between the supportingmembers and the sealing film; however, it is accompanied by a decreasesin the open area ratio, and as a result, the brightness and contrastratio of the liquid crystal display device is lowered so as todeteriorate the display quality. Therefore, the area for the supportingmembers in pixels is preferably 10% or less of the pixel area. In thatcase, however, the sealing film bonds only to the small area on thesupporting members, leaving the remaining part unstable, so thatinsufficient bonding between the supporting members and the sealing filmmay lead to a decrease in a yield.

The process of forming a gap between the substrate and the sealing filmby bonding the sealing film to the supporting members arranged on thesubstrate involves a difficult bonding of the sealing film to thelimited area on the supporting members.

In view of the problems hereinbefore, the inventors of the presentinvention have found that the problems of the invention on which thepresent invention is based can be solved by using a resin film as thesealing film and bonding the resin film directly to the supportingmembers.

One method of bonding the resin film to the substrate is heat sealing.In heat sealing, the substrate and the resin film stacked thereonto ispassed between a pair of rollers of a so-called laminator. Thethermoplastic resin film is bonded to the substrate because at least oneof the rollers is heated. This is an effective way to bond the resinfilm to the substrate without any gap therebetween. When the resin filmis bonded to the supporting members as the sealing film by this method,either the resin film or the supporting members must be thermoplastic.However, when the rollers are heated to a temperature at which the resinfilm exerts the thermoplastic characteristics, the resin film issoftened and deformed along the shape of the substrate and thesupporting members, failing to be bonded exclusively on the supportingmembers. On the other hand, when the rollers are heated to a temperatureat which the supporting members exert the thermoplastic characteristics,the supporting members are softened and crushed by the laminator. Wheneither the resin film or the supporting members are made thermoplasticlike this, a gap between the resin film and the substrate for sealingliquid crystal thereinto cannot be formed or becomes extremely narrow.

Third Prior Art

Liquid crystal display devices are widely used as portable informationterminal displays because of their being thin and light in weight. Sincea liquid crystal panel itself is a light-receptive device (a nonlight-emitting device), liquid crystal display devices with a liquidcrystal panel are generally classified into reflective type liquidcrystal display devices and permeable type liquid crystal displaydevices. The reflective type liquid crystal display devices are providedwith a reflective plate on the back surface of the liquid crystal panelso as to reflect external light, whereas the permeable type liquidcrystal display devices are provided with a back light on the backsurface of the liquid crystal panel so as to project the light from theback light.

As well known, liquid crystal can be driven with a low voltage ofseveral volts, and the reflective type liquid crystal display devices,which conduct image display by using external light instead of a backlight consume extremely low electric power.

When images are displayed in color on a normal reflective type liquidcrystal panel, micro color filters of red, green, and blue are providedon three adjacent pixels so as to perform the additive process. However,the color filters have a low light permittivity and requires apolarizing plate, and as a result, a reflective type liquid crystaldisplay device has a drawback of being incapable of displaying images inbright colors.

In order to realize bright color display without using a polarizingplate or color filters, the inventors of the present invention proposedreflective type color liquid crystal display devices including the onedisclosed in Japanese Laid-open Patent Application No. 6-286324. Thesereflective type color liquid crystal display devices comprise threeguest host liquid crystal layers of cyan, magenta, and yellow based onthe principle of a so-called subtractive process.

The reflective type color liquid crystal display devices will bedescribed as follows.

As shown in FIG. 83 a reflective type color liquid crystal displaydevice comprises three liquid crystal layers 1303-1305 filled with guesthost liquid crystals of cyan, magenta, and yellow, respectively, anddisposed between a bottom substrate 1301 and a top substrate 1302.

Thin film transistors (hereinafter referred to as TFT devices) 1306-1308and a first pixel electrode 1309 which also serves as a reflective filmare formed on the bottom substrate 1301. A first photosensitivepolyimide 1310 and a first insulator film 1311 supported by the firstphotosensitive polyimide 1310 are formed further thereon. A second pixelelectrode 1312 and a second photosensitive polyimide 1314 are formed onthe first insulator film 1311. The second pixel electrode 1312 isconnected with the TFT device 1307 via an opening portion 1313.

A third insulator film 1315 is further provided on the secondphotosensitive polyimide 1314 and supported thereby. A third pixelelectrode 1316 and a third photosensitive polyimide 1317 are provided onthe third insulator film 1315. The third pixel electrode 1316 isconnected with the TFT device 1308 via an opening portion 1318. A commonelectrode 1319 is provided on the third photosensitive polyimide 1317.The first liquid crystal layer 1303 is supplied with a voltage by thefirst and second pixel electrodes 1309 and 1312, the second liquidcrystal layer 1304 is supplied with a voltage by the second and thirdpixel electrodes 1312 and 1316, and the third liquid crystal layer 1305is supplied with a voltage by the third pixel electrode 1316 and thecommon electrode 1319.

However, the reflective type color liquid crystal display device leavesroom for improvement concerning the following. In general, the yield islikely to decrease along with the procession of the process of stackingthe liquid crystal sequentially on the TFT array substrate. When thereis a detect found in the liquid crystal layers, the expensive TFT arraysubstrate must be abandoned together with these layers, so that the costis increased.

In the case where simple matrix liquid crystal such as TN (TwistedNematic) or STN (Super Twisted Nematic) is used, the formation patternof the pixel electrodes provided on the substrate is different dependingto the type of device, so that an etching process must be changeddepending on the formation pattern of the pixel electrodes. As a result,the formation process of the pixel electrodes is complicated and theproduction cost of the liquid crystal panels is boosted, therebypreventing the reduction of the production cost. Especially in the caseof plastic liquid crystal panels, the plastic substrate itself is moreexpensive and inferior in heat resistance to a glass substrate, whichmakes it difficult to form and process transparent electrodes, therebyfurther increasing the cost.

SUMMARY OF THE INVENTION

In view of the current state of the art, the present invention has anobject of providing a liquid crystal display device whose productioncost is reduced by not requiring a mask alignment process in formingsupporting members, and whose contrast ratio is increased by reducingthe area for the supporting members, and further providing a method forfabricating the liquid crystal display device.

The present invention has another object of providing a liquid crystaldisplay device which can be used as a reflective type liquid crystaldisplay device for its bright display and a high contrast ratio, suffersno unevenness in color resulting from parallax, and has an improvedfabrication yield, and further providing a method for fabricating theliquid crystal display device.

The present invention has further another object of providing a liquidcrystal display device which has a simplified contact hole formationprocess and secures the connection between the electrodes and theconductive members.

The present invention has further another object of providing a liquidcrystal display device which prevents or reduces the occurrence ofwrinkles of the resin films when the electrodes are formed thereon byspattering.

The present invention has further another object of providing a liquidcrystal display device which offers an improved yield and a reducedfabrication cost, and further providing a method for fabricating theliquid crystal display device.

In order to achieve the objects, the liquid crystal display device ofclaim 1 comprises: a substrate having a pixel electrode and a drivingelement connected to the pixel electrode on a surface of the substrate;a resin film being disposed above the substrate and having a commonelectrode on a surface of the resin film; a plurality of supportingmembers each being columnar and standing on the substrate so as tosupport the resin film; an adhesive layer being disposed between theresin film and the plurality of supporting members so as to bond theresin film to the plurality of supporting members, the adhesive layerbeing made of a thermoplastic material and exerting thermoplasticcharacteristics so as to bond the resin film to the plurality ofsupporting members; and a liquid crystal layer being composed of liquidcrystal and being disposed between the substrate and the resin film.

Since the liquid crystal layer is formed by making a gap between thesubstrate and the resin film and then sealing liquid crystal thereinto,the liquid crystal makes up a large proportion of the liquid crystaldisplay device. As a result, the substantial open area ratio isincreased, thereby realizing a high contrast ratio and bright display.

Since the resin film is bonded to the supporting members by making theadhesive layer exert thermoplastic characteristics, it is prevented thatthe gap for sealing the liquid crystal thereinto is narrowed by thedeformation of the resin film along the supporting members, so that thegap has a fixed distance between the substrate and the resin film.Because the thickness of the liquid crystal layer is thus fixed, thedisplay performance is improved.

The liquid crystal display device of claim 2 comprises: a substratebeing transparent and having a pixel electrode and a driving elementconnected to the pixel electrode on a surface of the substrate; aplurality of resin films being stacked above the substrate, an uppermostresin film of the plurality of resin films having a common electrode ona surface thereof, and remaining ones of the plurality of resin filmseach having a pixel electrode on a surface thereof; a plurality ofliquid crystal layers each being formed by arranging a plurality ofsupporting members each being columnar in each gap between the substrateand a lowermost resin film of the plurality of resin films and betweenadjacent ones of the plurality of resin films, and by sealing liquidcrystal into the each gap; the substrate having more driving elements onthe surface thereof, the more driving elements being electricallyconnected to a corresponding one of the pixel electrodes formed on theremaining ones of the plurality of resin films via cubic interconnectionprovided in relation to each of the pixel electrodes formed on theremaining ones of the plurality of resin films; a plurality of adhesivelayers each being disposed between each of the plurality of supportingmembers and each of the plurality,of resin films, the plurality ofadhesive layers being made of a thermoplastic material and exertingthermoplastic characteristics so as to bond each of the plurality ofresin films to each of the plurality of supporting members; and thesupporting members between adjacent ones of the plurality of resin filmsbeing arranged substantially in same positions as the supporting membersbetween the substrate and the lowermost resin film with respect to aplane parallel to the substrate.

The liquid crystal display device has a multi-layered structurecomprising a plurality of resin films which have the same function asthe resin film of claim 1. Since the supporting members formed betweenadjacent resin films are arranged in the same position as those formedbetween the substrate and the lowermost resin film with respect to theplane parallel to the substrate, these supporting members are arrangedin straight lines in the direction vertical to the substrate. As aresult, the support of each resin film is secured, which prevents thepositional deviation between the supporting members formed on a layerand those on another layer, which would cause the deformation of thesupporting members or the destroy of the liquid crystal layers.

In the liquid crystal display device of claims 1 and 2, the plurality ofresin films can be made of either a material having no thermoplasticityor a material having thermoplasticity and exerting thermoplasticcharacteristics at a higher temperature than the plurality of adhesivelayers; and the plurality of supporting members can be made of either amaterial having no thermoplasticity, a material having thermoplasticityand exerting thermoplastic characteristics at a higher temperature thanthe plurality of adhesive layers, or a material being hardened beforethe plurality of resin films are bonded to the plurality of supportingmembers.

A combination of these resin films and the substrate makes it possibleto bond these resin films to the substrate without any of them beingdeformed.

In the liquid crystal display device of claim 2, three liquid crystallayers and three resin films can be stacked, and the liquid crystalscomposing the three liquid crystal layers can be guest host liquidcrystals each containing a dichroic dye, each dichroic dye having adifferent color from remaining dichroic dyes.

The above structure realizes a liquid crystal display device withfull-color display.

In the liquid crystal display device of claims and 2, the substrate canbe a transparent substrate; and the plurality of supporting members andthe plurality of adhesive layers can be a positive type photo resistformed by disposing a light shielding film over spots on the substratewhere the plurality of supporting members are arranged and by conductingphotolithography using the light shielding film as a photo mask.

The high precision in positioning the supporting members realizes adecrease in the area for the supporting members and an increase in thecontrast ratio.

In the multi-layered structure, the positional deviation between thesupporting members on each layer is minimized.

In the liquid crystal display device of claims 1 and 2, the substratecan be a transparent substrate; and the plurality of supporting membersand the plurality of adhesive layers can be a negative type photo resistformed by disposing a light shielding film on the substrate excludingspots where the plurality of supporting members are arranged and byconducting photolithography using the light shielding film as a photomask.

In the above structure, too, the precision in positioning the supportingmembers is improved.

In the liquid crystal display device of claims 1 and 2, the distancebetween adjacent ones of the plurality of supporting members arranged ina pixel region, of the plurality of supporting members can be in a rangeof 15 to 100 μm.

The distance between adjacent supporting members is limited because ofthe following reason. When the distance is too large, it makes eachresin film sag between adjacent supporting members and fails to maintainthe gaps, thereby causing unevenness in color or a decrease in thecontrast ratio. When the distance is too small, on the other hand, theopen area ratio is decreased by too many supporting members.

In the liquid crystal display device of claims 1 and 2, the thickness ofthe plurality of resin films can be in a range of 0.5 to 10 μm.

The thickness of the resin films is limited because of the followingreason. When the average thickness of the resin films is smaller than0.5 μm, the resin films are likely to wrinkle, whereas when it is largerthan 10 μm, the voltage drop in the resin films becomes too large ascompared with the voltage supplied to the liquid crystal layers.

In the liquid crystal display device of claims 1 and 2, the resistivityof the plurality of resin films can be 10¹⁰ Ω·cm or below.

The resistivity of each resin film is limited because when it is largerthan 10¹⁰Ω·cm, the voltage drop in each resin film becomes too large ascompared with the voltage supplied to the liquid crystal layers.

In the liquid crystal display device of claims 2 and 5, the plurality ofresin films can have optical anisotropy and are so arranged as to makeall slow axes of the plurality of resin films be in a same direction.

The above structure reduces the light attenuation due to the opticalanisotropy of the resin films, thereby realizing bright display.

In the liquid crystal display device of claims 1 and 2, the plurality ofresin films can have breathability, and the common electrode can be madeof a metallic material having reflection characteristics and also servesas a shading film for preventing oxygen or moisture in open air frompermeating through the uppermost resin film.

The structure prevents a decrease in display performance resulting fromthe permeation of oxygen or water in open air into the liquid crystallayers when the resin films have breathability.

In the liquid crystal display device of claims 1 and 2, the plurality ofresin films can have breathability, and a shading film can be providedon the common electrode so as to prevent oxygen or moisture in open airfrom permeating through the uppermost resin film.

The structure also prevents a decrease in display performance resultingfrom the permeation of oxygen or water in open air into the liquidcrystal layers when the resin films have breathability.

In the liquid crystal display device of claims 20 and 21, the commonelectrode can be a transparent electrode, and the shading film can bemade of a metallic material having reflection characteristics and alsoserve as a reflective plate.

The structure does not require a separate reflective plate and preventsa decrease in display performance resulting from the permeation ofoxygen and the other substances.

In the liquid crystal display device of claims 1 and 2, the commonelectrode can be a transparent electrode; a resin layer can be formed onthe common electrode, the resin layer being transparent and having amultiplicity of fine convex and concave portions on a surface thereof;and a reflective film having a shape of a multiplicity of fine convexand concave portions can be formed correspondingly on the multiplicityof fine convex and concave portions on the surface of the resin layer.

The structure makes the reflective film have diffusive light reflectioncharacteristics, thereby preventing a decrease in display performancedue to the reflection of the light source, as compared with a reflectivefilm having specular reflection.

The liquid crystal display device of claim 26 comprises: a substratehaving a pixel electrode and a driving element connected to the pixelelectrode on a surface of the substrate; a resin film being disposedabove the substrate; a plurality of supporting members each beingcolumnar and standing on the substrate so as to support the resin film;an adhesive layer being disposed between the resin film and th eplurality of supporting members so as to bond the resin film to theplurality of supporting members, the adhesive layer being made of athermoplastic material and exerting thermoplastic characteristics so asto bond the resin film to the plurality of supporting members; a liquidcrystal layer being composed of liquid crystal and being disposedbetween the substrate and the resin film; a resin layer being formed ona surface of the resin film, the resin layer being transparent andhaving a multiplicity of fine convex and concave portions on a surfacethereof; an d a reflective film having a shape of a multiplicity of fineconvex and concave portions and being formed correspondingly on themultiplicity of fine convex and concave portions on the surface of theresin layer, the reflective film also serving as a common electrode.

In addition to t he effects of preventing a decrease in displayperformance, no separate reflective film is required, which reduces thethickness of the liquid crystal display device and the number ofcomponents.

The liquid crystal display device of claim 27 comprises: a substratehaving a pixel electrode and a driving element connected to the pixelelectrode on a surface of the substrate; a plurality of resin filmsbeing stacked above the substrate, the plurality of resin films eachhaving a pixel electrode on a surface thereof except an uppermost resinfilm of the plurality of resin films; a plurality of liquid crystallayers each being formed by arranging a plurality of supporting memberseach being columnar in each gap between the substrate and a lowermostresin film of the plurality of resin films and between adjacent ones ofthe plurality of resin films, and by sealing liquid crystal into theeach gap; the substrate having more driving elements on the surfacethereof, the more driving elements being electrically connected to acorresponding one of the pixel electrodes formed on the plurality ofresin films except the uppermost resin film via cubic interconnectionprovided in relation to each of the pixel electrodes formed on theplurality of resin films except the uppermost resin film; a plurality ofadhesive layers each being disposed between each of the plurality ofsupporting members and each of the plurality of resin films, theplurality of adhesive layers being made of a thermoplastic material andexerting thermoplastic characteristics so as to bond each of theplurality of resin films to each of the plurality of supporting members;the supporting members between adjacent ones of the plurality of resinfilms being arranged substantially in same positions as the supportingmembers between the substrate and the lowermost resin film with respectto a plane parallel to the substrate; a resin layer being formed on asurface of the uppermost resin film, the resin layer being transparentand having a multiplicity of fine convex and concave portions on asurface thereof; and a reflective film having a shape of a multiplicityof fine convex and concave portions and being formed correspondingly onthe multiplicity of fine convex and concave portions on the surface ofthe resin layer, the reflective film also serving as a common electrode.

In addition to the effects of preventing a decrease in displayperformance, no separate reflective film is required, which reduces thethickness of the liquid crystal display device and the number ofcomponents.

The method for fabricating a liquid crystal display device of claim 28comprises the steps of: arranging a plurality of supporting members eachbeing columnar onto a substrate, the substrate being transparent andhaving a pixel electrode and a driving element connected with the pixelelectrode thereon; forming an adhesive layer onto the plurality ofsupporting members; bonding a resin film to the plurality of supportingmembers by disposing the resin film onto the adhesive layer formed onthe plurality of supporting members and applying heat to the resin filmwhile maintaining a gap between the substrate and the resin film;forming a common electrode onto a surface of the resin film; and sealingliquid crystal into the gap between the substrate and the resin film.

The structure enables the extremely thin resin film to be easily bondedonto the supporting members. Since the liquid crystal layer is formedbetween the substrate and the resin film by sealing liquid crystalthereinto, the liquid crystal makes up a larger proportion of the liquidcrystal display device. As a result, the substantial open area ratio isincreased so as to realize a high contrast ratio and bright display.

Furthermore, a decrease in the fabrication yield which might be causedin the invention on which the present invention is based can beprevented by the use of the resin film as a sealing film and the bondingof the resin film to the supporting members with the adhesive layertherebetween.

The method for fabricating a liquid crystal display device of claim 29comprises the steps of: arranging a plurality of first supportingmembers on a substrate, the substrate being transparent and having apixel electrode and a driving element connected to the pixel electrodethereon; forming a first adhesive layer onto the plurality first ofsupporting members; bonding a first resin film to the plurality of firstsupporting members by disposing the first resin film onto the firstadhesive layer formed on the plurality of first supporting members andapplying heat to the first resin film while maintaining a gap betweenthe substrate and the first resin film; forming a first opening portionin the first resin film; forming a first pixel electrode on the firstresin film and electrically connecting the first pixel electrode to acorresponding driving element on the substrate via the first openingportion; stacking one other resin film or more resin films by firststacking a second resin film while maintaining a gap between the firstresin film and the second resin film by arranging a plurality of secondsupporting members on the first resin film bonded to the plurality offirst supporting members; forming a second adhesive layer onto theplurality of second supporting members; bonding the second resin film tothe plurality of second supporting members; forming a second openingportion in the second resin film; and forming a second pixel electrodeon the second resin film and electrically connecting the second pixelelectrode to a corresponding driving element formed on the substrate viathe second opening portion; forming a plurality of uppermost supportingmembers on a resin film last stacked in a previous stacking step anddisposing an uppermost adhesive layer onto the plurality of uppermostsupporting members so as to bond an uppermost resin film to theplurality of uppermost supporting members; forming a common electrode ona surface of the uppermost resin film; and sealing liquid crystal intothe gap between the substrate and the first resin film and the gapbetween adjacent resin films.

According to the structure, a liquid crystal display device having amulti-layered structure which has the same function as the displaydevice of claim 28 is fabricated.

In the method for fabricating a liquid crystal display device of claim29, each opening portion can be formed by reactive ion etching.

As a result, it is secured to form each opening portion in the resinfilms.

In the method for fabricating a liquid crystal display device of claims28 and 29, the step of bonding the first resin to the plurality of firstsupporting members and the step of stacking one other resin film or moreresin films each can comprise the sub step of pressing each resin filmwith a heated roller.

The use of the heated roller secures the bonding of the reins films ontothe supporting members within a short time.

In the method for fabricating a liquid crystal display device of claim32, each adhesive layer can be made of a material which exertsthermoplastic characteristics at a lower temperature than each resinfilm exerting thermoplastic characteristics, and the heated roller canheat the each resin film to a temperature lower than the each resin filmexerting thermoplastic characteristics and higher than the each adhesivelayer exerting thermoplastic characteristics.

According to the structure, the heated roller plasticizes each adhesivelayer and each resin film is bonded to the supporting members via theadhesive layer. Since the supporting members and the resin films do notplasticize, the deformation of the resin films along the supportingmembers and the destroy of the supporting members are prevented. As aresult, the resin films are easily bonded onto the supporting memberswhile the gaps corresponding to the height of the supporting members aremaintained.

In the method for fabricating a liquid crystal display device of claim32, at least a surface of the heated roller can be made of a rigidmaterial.

According to the structure, the resin films are smoothly bonded onto thesupporting members without being encroached by the supporting members.As a result, each liquid crystal layer has even thickness, so thatunevenness and defects in display are prevented.

In the method for fabricating a liquid crystal display device of claim28, the step of arranging the plurality of supporting members onto thesubstrate can comprise: forming a light shielding film over spots on asurface of the substrate where the plurality of supporting members arearranged; applying a first positive type resist onto the surface of thesubstrate; exposing the first positive type resist from a rear surfaceof the substrate using the light shielding film as a photo mask; anddeveloping the first positive type resist with a first developingsolution and hardening the first positive type resist; and the step offorming the adhesive layer onto the plurality of supporting memberscomprises: applying a second positive type resist onto the surface ofthe substrate having the plurality of supporting members thereon;exposing the second positive type resist from the rear surface of thesubstrate using the light shielding film as the photo mask; anddeveloping the second positive type resist with a second developingsolution.

Since the structure requires no mask alignment between the adhesivelayer and the supporting members, the fabrication of the liquid crystaldisplay device is simplified.

In the method for fabricating a liquid crystal display device of claims28 and 29, the step of forming an adhesive layer and the step of bondingthe first resin film to the plurality of first supporting memberscomprise: preparing the first resin film applied with an adhesive layer;and arranging the first resin film onto the plurality of firstsupporting members with heating so that the surface applied with theadhesive layer faces the plurality of first supporting members; and thestep of stacking one other resin film or more resin films comprises:preparing the second resin film applied with an other adhesive layer;and arranging the second resin film onto the plurality of secondsupporting members with heating so that the surface applied with theother adhesive layer faces the plurality of second supporting members.

Since the structure does not require the step of forming the adhesivelayer onto the supporting members, the fabrication of the liquid crystaldisplay device is simplified.

In the method for fabricating a liquid crystal display device of claims28 and 29, in the step of arranging the plurality of supporting memberson the substrate, supporting members arranged in a pixel region can beformed to have more width than height.

The structure prevents the supporting members from being crushed by theroller when the supporting members with the resin film stacked thereonpasses through the laminator. As a result, the fabrication yield isincreased.

In the method for fabricating a liquid crystal display device of claims28 and 29, the thickness of each resin film can be in a range of 0.5 to10 μm.

The thickness of each resin film is limited because of the followingreason. When the average thickness of the resin films is smaller than0.5 μm, the resin films are likely to wrinkle, whereas when it is largerthan 10 μm, the voltage drop in the resin films becomes too large ascompared with the voltage supplied to the liquid crystal layers.

In the method for fabricating a liquid crystal display device of claims28 and 29, the main component of each resin film can be a polyesterresin.

The resin films have enough strength not to be broken during thefabrication of the liquid crystal display device, so that thefabrication yield is increased. Since the polyester resin is transparenthaving a small light attenuation in a visible wavelength range, itprovides bright display as a liquid crystal display device.

In the method for fabricating a liquid crystal display device of claim28, in the step of bonding the resin film to the plurality of supportingmembers, a venthole can be formed in order to ventilate the gap betweenthe substrate and the resin film.

According to the structure, in the process involving heating or vacuumevacuation, the ventilation through the venthole prevents the resin filmfrom being broken by the expansion of the air in the gap between thesubstrate and the resin film. As a result, a decrease in the yield isrestricted.

In the method for fabricating a liquid crystal display device of claim29, in the step of bonding the first resin film to the plurality offirst supporting members, a first venthole can be formed in order toventilate the gap between the substrate and the first resin film; and inthe step of stacking one other resin film or more resin films, a secondventhole can be formed in order to ventilate the gap between the firstresin film and the second resin film.

According to the structure, in the process involving heating or vacuumevacuation, the ventilation through the venthole prevents the resinfilms from being broken by the expansion of the air in the gaps betweenthe substrate and the lowermost resin film and between adjacent resinfilms. As a result, a decrease in the yield is restricted.

In the method for fabricating a liquid crystal display device of claim46, the venthole can be formed by leaving a part of the substratewithout being bonded to the resin film, the part being in a vicinity ofa display portion on the substrate.

The structure facilitates the formation of the venthole, therebysimplifying the fabrication processes of the liquid crystal displaydevice.

In the method for fabricating a liquid crystal display device of claim47, the second venthole can be formed by leaving a part of the firstresin film without being bonded to the second resin film, the part beingin a vicinity of a display portion on the substrate.

The structure facilitates the formation of the venthole, therebysimplifying the fabrication processes of the liquid crystal displaydevice.

In the method for fabricating a liquid crystal display device of claim49, the internal wall of the venthole can be subjected to a treatmentfor decreasing a surface tension.

When the process of heating or vacuum evacuating and the process ofsoaking in the solution are alternately performed, the opening andclosing of the ventholes do not need to be repeated, which simplifiesthe fabrication processes of the liquid crystal display device.

In the method for fabricating a liquid crystal display device of claim46, the venthole can be formed by bonding the resin film to thesubstrate in a vicinity of a display portion on the substrate so as toonce seal the gap, and forming a through hole in a region outside adisplay portion of the resin film.

The structure facilitates the formation of the venthole, therebysimplifying the fabrication processes of the liquid crystal displaydevice.

In the method for fabricating a liquid crystal display device of claim47, the first venthole and the second venthole can be formed by bondingthe first resin film to the substrate and bonding the second resin filmto the first resin film in a vicinity of a display portion on thesubstrate so as to once seal the gap between the substrate and the firstresin film and the gap between the first resin film and the second resinfilm, and forming a through hole in a region outside a display portionof all resin films stacked.

The structure facilitates the formation of the ventholes, therebysimplifying the fabrication processes of the liquid crystal displaydevice.

The method for fabricating a liquid crystal display device of claims 46and 47 further comprises the step of closing the ventholes.

In the process involving soaking in the solution, the solution isprevented from permeating through the ventholes, which increases theyield.

The method for fabricating a liquid crystal display device of claim 56comprises the steps of: arranging a plurality of supporting members eachbeing columnar onto a substrate, the substrate being transparent andhaving a pixel electrode and a driving element connected with the pixelelectrode thereon; forming an adhesive layer onto the plurality ofsupporting members; bonding a resin film to the plurality of supportingmembers by disposing the resin film onto the adhesive layer formed onthe plurality of supporting members and applying heat to the resin filmwhile maintaining a gap between the substrate and the resin film;forming a resin layer whose surface has a multiplicity of fine convexand concave portions by applying a photo resist onto a surface of theresin film, subjecting the surface of the resin film to mask exposure,developing, and baking; forming a reflective film also serving as acommon electrode onto the surface of the resin layer; and sealing liquidcrystal into the gap between the substrate and the resin film.

The structure enables the reflective film having diffusion to be easilyformed on the resin layer.

The method for fabricating a liquid crystal display device of claim 57comprises the steps of: arranging a plurality of first supportingmembers each being columnar on a substrate, the substrate beingtransparent and having a pixel electrode and a driving element connectedto the pixel electrode thereon; forming a first adhesive layer onto theplurality of first supporting members; bonding a first resin film to theplurality of first supporting members by disposing the first resin filmonto the first adhesive layer formed on the plurality of firstsupporting members and applying heat to the first resin film whilemaintaining a gap between the substrate and the first resin film;forming a first opening portion in the first resin film; forming a firstpixel electrode on the first resin film and electrically connecting thefirst pixel electrode to a corresponding driving element on thesubstrate via the first opening portion; stacking one other resin filmor more resin films by first stacking a second resin film whilemaintaining a gap between the first resin film and the second resin filmby arranging a plurality of second supporting members on the first resinfilm bonded to the plurality of first supporting members; forming asecond adhesive layer onto the plurality of second supporting members;bonding the second resin film to the plurality of second supportingmembers; forming a second opening portion in the second resin film; andforming a second pixel electrode on the second resin film andelectrically connecting the second pixel electrode to a correspondingdriving element formed on the substrate via the second opening portion;forming a plurality of uppermost supporting members on a resin film laststacked in a previous stacking step and disposing an uppermost adhesivelayer onto the plurality of uppermost supporting members so as to bondan uppermost resin film to the plurality of uppermost supportingmembers; forming a resin layer whose surface has a multiplicity of fineconvex and concave portions by applying a photo resist onto a surface ofthe uppermost resin film, subjecting the surface of the uppermost resinfilm to mask exposure, developing, and baking; forming a reflective filmalso serving as a common electrode onto the surface of the resin layer;and sealing liquid crystal into the gap between the substrate and thefirst resin film and the gap between adjacent resin films.

The structure enables the reflective film having diffusion to be easilyformed above the liquid crystal layer.

In another embodiment,

a plurality of resin films being stacked, the plurality of resin filmsincluding at least two resin films having electrodes thereon; liquidcrystal layers each arranged between adjacent ones of the plurality ofresin films stacked; a contact hole being formed so as to penetrate allof the plurality of resin films; at least part of each of predeterminedelectrodes of the electrodes being projected and exposed inside thecontact hole; and the part of each of predetermined electrodes being incontact with a conductive member formed on an internal surface of thecontact hole so as to connect the predetermined electrodes electrically.

Since the contact hole is formed so as to penetrate all the resin filmsstacked, any electrodes on the resin films can be connected with eachother. The conductive member and the electrodes have a large contactarea because the conductive member is in contact with the exposed partsof the electrodes. Consequently, the connection between the conductivemember and the electrodes is secured, making it possible to realize aliquid crystal display device with reliable electric connection.

In the liquid crystal display, the plurality of resin films can at leastinclude a first resin film and a second resin film arranged above thefirst resin film; the contact hole can have a larger size in the secondresin film than in the first resin film; and the electrode on the firstresin film can be projected and exposed inside the contact hole.

The internal surface of the contact hole is formed to have some stepsand the electrode on the first resin film has a surface with steps. As aresult, the connection between the electrode and the conductive memberis secured.

In another embodiment, a plurality of resin films being stacked andhaving electrodes thereon, and liquid crystal layers each being arrangedbetween adjacent ones of the plurality of resin films, wherein aplurality of contact holes being formed so as to penetrate all of theplurality of resin films; and predetermined electrodes of the electrodesbeing electrically connected via each conductive member formed on aninternal surface of each of the plurality of contact holes.

Since some electrodes are connected in each contact hole, desiredelectrodes can be connected with each other. This structure is effectivewhen complicated cubic interconnection is required.

In the liquid crystal display device, part of each of the predeterminedelectrodes can be exposed inside the plurality of contact holes so as tobe connected with the each conductive member.

The conductive members and the electrodes have a large contact areabecause the conductive members are in contact with the exposed parts ofthe electrodes. Consequently, the connection between the conductivemembers and the electrodes is secured.

In the liquid crystal display device, the part of each of thepredetermined electrodes can be projected and exposed inside theplurality of contact holes.

Since part of each electrode is projected and exposed inside the contactholes, the conductive members and the electrodes have a larger contactarea. Consequently, the connection between the conductive members andthe electrodes is secured.

In the liquid crystal display device,

a substrate at least having a first driving element and a second drivingelement thereon; at least a first resin film having a first electrodethereon and a second resin film having a second electrode thereon, thesecond resin film being stacked on the first resin film; and liquidcrystal layers each arranged between the substrate and the first resinfilm and between the first resin film and the second resin film; atleast a first contact hole and a second contact hole each penetrating atleast the first resin film and the second resin film when the firstresin film and the second resin film are stacked on the substrate; afirst conductive member being formed on an internal surface of the firstcontact hole in order to electrically connect the first driving elementand the first electrode; and a second conductive member being formed onan internal surface of the second contact hole in order to electricallyconnect the second driving element and the second electrode.

The electric connection between the driving elements and the electrodesmakes it possible to control the voltage supply to the electrodes by thedriving elements.

In the liquid crystal display device, part of each of the firstelectrode and the second electrode can be exposed inside the firstcontact hole and the second contact hole so as to be connected with thefirst conductive member and the second conductive member.

The structure secures the connection between the first and secondconductive members and the first and second electrodes.

In the liquid crystal display device, the part of each of the firstelectrode and the second electrode can be projected and exposed insidethe first contact hole and the second contact hole.

Since part of each of the first and second electrodes is projected andexposed inside the contact holes, the conductive members and theseelectrodes have a larger contact area. As a result, the connectionbetween the conductive members and the first and second electrodes issecured.

In the liquid crystal display device, the first contact hole and thesecond contact hole can have a larger size in the second resin film thanin the first resin film.

The internal surface of each contact hole is formed to have steps andthe electrode on the first resin film has a surface with steps. As aresult, the connection between the electrodes and the conductive membersis secured.

In the liquid crystal display device,

a substrate having a pixel electrode and a pixel switching elementconnected to the pixel electrode thereon; a plurality of resin filmsbeing stacked on the substrate, an uppermost resin film of the pluralityof resin films having a common electrode thereon and remaining ones ofthe plurality of resin films having pixel electrodes thereon; aplurality of liquid crystal layers each being arranged between thesubstrate and a lowermost resin film of the plurality of resin films andbetween adjacent ones of the plurality of resin films; a plurality ofdriving elements being arranged on the substrate and a corresponding oneof the pixel electrodes arranged on the remaining ones of the pluralityof resin films; a plurality of cubic interconnection pads each beingarranged between the substrate and the lowermost resin film and betweenadjacent ones of the plurality of resin films; a plurality of contactholes each penetrating all of the plurality of cubic interconnectionpads and all of the plurality of resin films and corresponding to one ofthe pixel electrodes; and a plurality of conductive members each beingformed on an internal surface of a corresponding one of the plurality ofcontact holes so as to electrically connect each of the plurality ofdriving elements to a corresponding one of the pixel electrodes.

The structure makes it possible to control the voltage supply to eachpixel electrode by the driving elements on the substrate, therebyobtaining a liquid crystal display device having a multi-layeredstructure with resin films.

In the liquid crystal display device, part of each of the pixelelectrodes can be exposed inside a corresponding one of the plurality ofcontact holes so as to be connected with a corresponding one of theplurality of conductive members.

The conductive members and the pixel electrodes have a large contactarea because the conductive members are in contact with the exposedparts of the electrodes. Consequently, the connection between theconductive members and the electrodes is secured, making it possible torealize a liquid crystal display device with reliable electricconnection.

In the liquid crystal display device, the part of each of the pixelelectrodes can be projected and exposed inside the corresponding one ofthe plurality of contact holes.

Since part of each pixel electrode is projected and exposed inside acorresponding contact hole, the conductive members and the pixelelectrodes have a larger contact area. As a result, the connectionbetween the pixel electrode and the conductive members is secured.

In the liquid crystal display device, the plurality of contact holes canhave a larger size in upper resin films than in lower resin films of theplurality of resin films.

The internal surface of each contact hole is formed to have steps andthe electrodes on lower resin films each have a surface with steps. As aresult, the connection between the electrodes and the conductive membersis secured.

In the liquid crystal display device, the electrodes can be made of amaterial resistant to dry etching, and the contact holes can be formedby a dry etching treatment.

By the dry etching treatment, the electrodes are projected and exposedinside the contact holes.

The method for fabricating a liquid crystal display device comprises thesteps of: stacking a plurality of resin films having electrodes thereon;forming a plurality of contact holes each penetrating all of theplurality of resin films; and filling the plurality of contact holeswith a conductive member so as to electrically connect predeterminedones of the electrodes each other via the conductive member.

The structure makes desired electrodes be connected with each other byperforming the contact hole formation process only once, therebysimplifying the process as compared with the conventional methods.

The method for fabricating a liquid crystal display device comprises thesteps of: stacking a first resin film having a first electrode thereonand a second resin film having a second electrode thereon in that orderonto a substrate having at least a first driving element and a seconddriving element;

forming a first contact hole and a second contact hole each penetratingat least the first resin film and the second resin film; and filling thefirst contact hole with a first conductive member and filling the secondcontact hole with a second conductive member so as to connect the firstdriving element and the first electrode via the first conductive memberand to connect the second driving element and the second electrode viathe second conductive member.

The structure makes desired electrodes be connected with the drivingelements by performing the contact hole formation process only once,thereby simplifying the process as compared with the conventionalmethods.

The method for fabricating a liquid crystal display device comprises aplurality of resin films being stacked and having electrodes made from amaterial resistant to dry etching thereon; and a contact holepenetrating the plurality of resin films so as to electrically connectpredetermined electrodes of the electrodes, the method comprising thesteps of: forming only the predetermined electrodes onto correspondingones of the plurality of resin films, and removing part of each of thepredetermined electrodes where the contact hole is formed in a mannerthat the part removed is larger in upper ones of the plurality of resinfilms; and forming the contact hole by dry etching.

The electrodes have resistance to dry etching and the resin films donot, so that only the resin films are removed by the dry etching. Onlythe predetermined electrodes in the region to form the contact hole areremoved largely in upper electrodes. As a result, when the contact holeis formed, only the predetermined electrodes are projected and exposedinside the contact hole. Consequently, the connection between thepredetermined electrodes and the conductive members is secured, whichimproves the reliability of the connection between the predeterminedelectrodes.

The liquid crystal display device comprises: a resin film; a wrinklereduction layer being formed on the resin film and having a shockresistance to spattering; and an electrode being made of an inorganicmaterial and formed on the wrinkle reduction layer by spattering.

The structure makes it possible to prevent the resin film from wrinklingwhen the electrode made of an inorganic material such as ITO is formedthereon by spattering.

In the liquid crystal display device, the thickness of the resin filmcan be less than 10 μm.

The thickness of the resin film is limited because of the followingreason. When the thickness is smaller than 10 μm, the resin film islikely to wrinkle unless the wrinkle reduction layer is provided becauseits shock resistance is too small.

In the liquid crystal display device, the wrinkle reduction layer can bemade of either an organic resin containing silica particles or anacrylic resin.

The organic resin containing silica particles and the acrylic resinsecurely prevent the resin film from wrinkling because they have largeshock resistance to spattering.

In the liquid crystal display device, the resin film can be arranged ona substrate with a spacer therebetween so as to keep a gap between theresin film and the substrate, the gap being filled with liquid crystal.

According to the structure, a liquid crystal display device with awrinkle-free resin film is realized. As a result, the displaycharacteristics are improved, with no unnecessary diffusion caused by awrinkled resin film.

The liquid crystal display device comprises: a substrate being made of atransparent material and having a reflective film thereon; a sealingplate being formed so as to face the reflective film formed on thesubstrate; a liquid crystal layer being disposed between the substrateand the sealing plate; an opening portion formed on the reflective film;and a supporting member supporting the sealing plate and being arrangedin a position between the substrate and the sealing plate, the positioncorresponding to the opening portion of the reflective film, and thesupporting member being formed by exposing a photosensitive resin viathe opening portion.

The high precision in positioning the supporting member makes itpossible to reduce the area for the supporting member, therebyincreasing the contrast ratio.

In the liquid crystal display device, the photosensitive resin can be anegative type resist.

The supporting member is easily obtained by exposing the photosensitiveresin through the opening portion.

In the liquid crystal display device, the liquid crystal layer cancomprise a polymer and liquid crystal which is dispersedly held in thepolymer.

This structure realizes a liquid crystal display device in which thesealing plate is securely fixed onto the supporting member by thepolymer in the liquid crystal layer.

In the liquid crystal display device, the photosensitive resin can be aphotosensitive polymer precursor contained in a mixture solutioncomprising liquid crystal for composing the liquid crystal layer and thephotosensitive polymer precursor.

The liquid crystal layer is made from the liquid crystal which is leftunconsumed for the formation of the supporting member by the exposure ofthe mixture solution, so that the obtained liquid crystal display devicehas a large substantial open area ratio and a high contrast ratio.

In the liquid crystal display device, a plurality of liquid crystallayers and a plurality of sealing plates can be arranged alternately onthe substrate, and a plurality of supporting members for supporting theplurality of sealing plates can be each arranged in each positionbetween adjacent ones of the plurality of sealing plates, the eachposition corresponding to the opening portion of the reflective film,the plurality of supporting members being formed by exposing thephotosensitive resin via the opening portion.

As a result, a liquid crystal display device which can display colorimages is achieved.

In the liquid crystal display device, three liquid crystal layers andthree sealing plates can be arranged alternately, and the three liquidcrystal layers each can have guest host liquid crystal containing liquidcrystal and a dichroic dye having a color of cyan, magenta, or yellow,each dichroic dye having a different color from remaining dichroic dyes.

As a result, a liquid crystal display device which can displayfull-color images is achieved.

The method for fabricating a liquid crystal display device comprises thesteps of: forming a reflective film having an opening portion onto atransparent substrate; forming a photosensitive resin layer onto thesubstrate having the reflective film thereon; exposing thephotosensitive resin layer from the substrate side via the openingportion of the reflective film so as to be hardened; forming asupporting member by removing part of the photosensitive resin layer bydeveloping, the part being prevented from being exposed due to shieldingof the reflective film; bonding a sealing plate to the supportingmember; and forming a liquid crystal layer between the substrate and thesealing plate by sealing liquid crystal thereinto.

The supporting member is securely formed in the position of the openingportion so as to increase its positional precision, so that the area forthe supporting member can be reduced without damaging the liquid crystallayer by the positional deviation of the supporting member. As a result,a liquid crystal display device with a high contrast ratio is obtained.Furthermore, mask alignment becomes unnecessary because no mask is used,so that the fabrication cost is reduced.

In the method for fabricating a liquid crystal display device, thephotosensitive resin layer can be made from a negative type resist.

Since the structure allows the supporting member to be made of a commonmaterial, it can be formed easily and at a lower cost.

In the method for fabricating a liquid crystal display device, the stepof forming the liquid crystal layer can comprise the sub steps of:sealing a mixture solution into between the substrate and the sealingplate, the mixture solution containing liquid crystal and aphotosensitive polymer precursor; and exposing the mixture solution fromthe sealing plate side so as to harden the polymer precursor containedin the mixture solution, thereby forming the liquid crystal layercomprising polymer and the liquid crystal dispersedly held in thepolymer, and also fixing the sealing plate onto the substrate.

As a result, the sealing plate is easily and securely fixed to thesubstrate by using the polymer hardened by exposure.

In the method for fabricating a liquid crystal display device, the stepof bonding the sealing plate to the supporting member can comprise thesub steps of: applying an adhesive agent onto at least one of thesupporting member and the sealing plate; and fixing the sealing plateonto the substrate.

In the method for fabricating a liquid crystal display device, at leastone of the sealing plate and the supporting member can be made of amaterial plasticized by at least one of heat and pressure; and the stepof fixing the sealing plate onto the substrate can be conducted byapplying at least one of heat and pressure while the sealing plate isbeing in close contact with the supporting member.

The sealing plate is easily and securely fixed to the substrate withoutusing the mixture solution containing liquid crystal and thephotosensitive polymer precursor. As a result, the area for the liquidcrystal in the liquid crystal layer is increased in order to increasethe substantial open area ratio, which realizes a liquid crystal displaydevice having a higher contrast ratio.

In the method for fabricating a liquid crystal display device, at leastone other liquid crystal layer can be formed by conducting the steps of:forming a second photosensitive resin layer onto the sealing plate;exposing the second photosensitive resin layer via the opening portionof the reflective film and the supporting member from the substrate sideso as to be hardened; forming a second supporting member by removingpart of the second photosensitive resin layer by developing, the partbeing prevented from being exposed by shielding of the reflective film;bonding a second sealing plate to the second supporting member; andforming a second liquid crystal layer between the sealing plate and thesecond sealing plate by sealing liquid crystal thereinto.

As a result, a liquid crystal display device which can display colorimages is achieved.

The method for fabricating a liquid crystal display device comprises thesteps of: forming a reflective film having an opening portion onto atransparent substrate; arranging a supplemental supporting member in apredetermined region on the substrate, the predetermined region isoutside the opening portion of the reflective film; bonding a sealingplate to the supplemental supporting member; sealing a mixture solutioninto between the substrate and the sealing plate, the mixture solutioncontaining liquid crystal and a photosensitive polymer precursor; andforming a supporting member by exposing the mixture solution from thesubstrate side via the opening portion and precipitating the polymerprecursor contained in the mixture solution in a position correspondingto the opening portion so as to harden the polymer precursor, and alsomaking a liquid crystal layer from the liquid crystal contained in themixture solution left unused for formation of the supporting member.

The supporting member is securely formed in the position of the openingportion so as to increase its positional precision, so that the area forthe supporting member can be reduced without damaging the liquid crystallayer by the positional deviation of the supporting member. Furthermore,the liquid crystal layer is made from the liquid crystal which is leftunconsumed for the formation of the supporting member by the exposure ofthe mixture solution, so that the obtained liquid crystal display devicehas a large substantial open area ratio and a high contrast ratio. Inaddition, mask alignment becomes unnecessary because no mask is used, sothat the fabrication cost is reduced.

In the method for fabricating a liquid crystal display device, the stepof arranging the supplementary supporting member can comprise the substeps of: forming a negative type resist layer onto the substrate havingthe reflective film thereon; exposing the negative type resist layer viaa predetermined mask pattern from an opposite side of the substrate soas to be hardened; and removing part of the negative type resist layerby developing, the part being prevented form being exposed by shieldingof the mask pattern.

Since the structure allows the supplemental supporting member to be madeof a common material, it can be formed easily and at a lower cost.

In the method for fabricating a liquid crystal display device, at leastone other liquid crystal layer can be formed by conducting the steps of:forming a second supplemental supporting member in a positioncorresponding to the supplemental supporting member formed on thesealing plate; bonding a second sealing plate onto the secondsupplemental supporting member; sealing a second mixture solution intobetween the sealing plate and the second sealing plate, the secondmixture solution containing liquid crystal and a photosensitive polymerprecursor; and forming a second supporting member by exposing the secondmixture solution from the substrate side via the opening portion and thesupporting member and precipitating the polymer precursor contained inthe second mixture solution in a position corresponding to the openingportion so as to be hardened, and also making a second liquid crystallayer from the liquid crystal contained in the second mixture solutionleft unused for formation of the second supporting member.

As a result, a liquid crystal display device which can display colorimages is achieved.

The method for fabricating a liquid crystal display device comprises thesteps of: forming a reflective film having an opening portion onto asubstrate, the opening portion comprising a first opening portion and asecond opening portion; forming a photosensitive resin layer onto thesubstrate having the reflective film thereon; covering the secondopening portion with a first masking member from the substrate side, andexposing the photosensitive resin layer via the first opening portionfrom the substrate side so as to be hardened; forming a first-partsupporting member of a supporting member by removing part of thephotosensitive resin layer by developing, the part being prevented frombeing exposed by shielding of the reflective film and the first maskingmember; bonding a sealing plate to the first-part supporting member;sealing a mixture solution into between the substrate and the sealingplate, the mixture solution containing liquid crystal and aphotosensitive polymer precursor; and forming a second-part supportingmember of the supporting member by covering the first opening portionwith a second masking member, exposing the mixture solution from thesubstrate side via the second opening portion, and precipitating thepolymer precursor contained in the mixture solution in a positioncorresponding to the second opening portion so as to be hardened, andalso making a liquid crystal layer from the liquid crystal contained inthe mixture solution left unused for formation of the second-partsupporting member.

The first-part supporting member makes the gap between the substrate andthe sealing plate have uniform thickness so as to keep the balance ofthe display colors of the liquid crystal display device. Furthermore,the liquid crystal layer is made from the liquid crystal which is leftunconsumed for the formation of the supporting member by the exposure ofthe mixture solution, so that the obtained liquid crystal display devicehas a large substantial open area ratio and a high contrast ratio.

In the method for fabricating a liquid crystal display device, at leastone other liquid crystal layer can be formed by conducting the steps of:forming a second photosensitive resin layer onto the sealing plate;covering the second opening portion with the first masking member fromthe substrate side, and exposing the second photosensitive resin layervia the first opening portion and the first-part supporting member fromthe substrate side so as to be hardened; forming an additionalfirst-part supporting member by removing part of the secondphotosensitive resin layer by developing, the part being prevented formbeing exposed by shielding of the reflective film and the first maskingmember; bonding a second sealing plate to the additional first-partsupporting member; sealing a second mixture solution into between thesealing plate and the second sealing plate, the second mixture solutioncontaining a liquid crystal and a photosensitive polymer precursor; andforming an additional second-part supporting member by covering thefirst opening portion with the second masking member from the substrateside, exposing the second mixture solution from the substrate side viathe second opening portion and the second-part supporting member, andprecipitating a polymer precursor contained in the second mixturesolution in a position corresponding to the second opening portion so asto be hardened, and also making a second liquid crystal layer from theliquid crystal contained in the second mixture solution left unused forformation of the additional second-part supporting member.

As a result, a liquid crystal display device which can display colorimages is achieved.

The liquid crystal display device comprises: a substrate made of atransparent material; a sealing plate arranged so as to face thesubstrate; a liquid crystal layer disposed between the substrate and thesealing plate; a light shielding film is formed on a predeterminedregion of the substrate; and a supporting member supporting the sealingplate and being arranged in a position between the substrate and thesealing plate where the light shielding film is formed, the supportingmember being formed by exposing part of a photosensitive resin where thelight shielding film is not formed.

Since the supporting member has high positional precision, the area forthe supporting member can be reduced so as to increase the contrastratio.

In the liquid crystal display device, the photosensitive resin can be apositive type resist, and the light shielding film can be made of ablack resist.

The supporting member can be easily obtained by exposing the part of thephotosensitive resin where the light shielding film is not formed.

In the liquid crystal display device, the liquid crystal layer cancomprise a polymer and liquid crystal which is dispersedly held in thepolymer.

In the obtained liquid crystal display device, the sealing plate issecurely fixed onto the supporting member by the polymer contained inthe liquid crystal layer.

In the liquid crystal display device, a plurality of liquid crystallayers and a plurality of sealing plates can be arranged alternately onthe substrate, and a plurality of supporting members for supporting theplurality of sealing plates can be each arranged in each positionbetween adjacent ones of the plurality of sealing plates, where thelight shielding film is formed, the plurality of supporting membersbeing formed by exposing the photosensitive resin via the part where thelight shielding film is not formed.

As a result, a liquid crystal display device which can display colorimages is achieved.

The method for fabricating a liquid crystal display device comprises thesteps of: forming a light shielding film in a predetermined region on asubstrate; forming a photosensitive resin layer onto the substratehaving the light shielding film thereon; exposing part of thephotosensitive resin layer from the substrate side, the partcorresponding to a region on the substrate where the light shieldingfilm is not formed; removing an exposed part of the photosensitive resinlayer by developing, thereby forming a supporting member in a positioncorresponding to the predetermined region where the light shielding filmis formed; bonding a sealing plate to the supporting member; and forminga liquid crystal layer between the substrate and the sealing plate bysealing liquid crystal thereinto.

The supporting member is securely formed in the position correspondingto the opening portion so as to increase its positional precision, sothat the area for the supporting member can be reduced without damagingthe liquid crystal layer by the positional deviation of the supportingmember. As a result, the obtained liquid crystal display device has ahigh contrast ratio. In addition, mask alignment becomes unnecessarybecause no mask is used, so that the fabrication cost is reduced.

In the method for fabricating a liquid crystal display device, thephotosensitive resin layer can be made of a positive type resist.

Since the structure allows the supporting member to be made of a commonmaterial, it can be formed easily and at a lower cost.

In the method for fabricating a liquid crystal display device, the stepof forming the liquid crystal layer can comprise the sub steps of:sealing a mixture solution into between the substrate and the sealingplate, the mixture solution containing liquid crystal and aphotosensitive polymer precursor; and exposing the mixture solution fromthe sealing plate side so as to harden the polymer precursor containedin the mixture solution, thereby forming the liquid crystal layercomprising polymer and liquid crystal dispersedly held in the polymer,and also fixing the sealing plate onto the substrate.

As a result, the sealing plate is easily and securely fixed to thesubstrate by using the polymer hardened by exposure.

In the method for fabricating a liquid crystal display device, at leastone other liquid crystal layer can be formed by conducting the steps of:forming a second photosensitive resin layer onto the sealing plate;exposing part of the second photosensitive resin layer, the partcorresponding to the region of the substrate where the light shieldingfilm is not formed; removing an exposed part of the secondphotosensitive resin layer, thereby forming a second supporting memberin a position corresponding to the predetermined region where the lightshielding film is formed; bonding a second sealing plate to the secondsupporting member; and forming a second liquid crystal layer between thesealing plate and the second sealing plate by sealing liquid crystalthereinto.

As a result, a liquid crystal display device which can display colorimages is achieved.

The liquid crystal display comprises: a display layer being composed ofa substrate having a common electrode on an internal surface thereof, asealing plate supported by a supporting member arranged on the commonelectrode, a liquid crystal layer formed between the substrate and thesealing plate by sealing liquid crystal thereinto, and a pixel electrodedisposed on a surface of the sealing plate, the surface being oppositethe liquid crystal layer; an array substrate having a non-linear elementfor driving the liquid crystal layer and an output electrode beingelectrically connected with the non-linear element and supplying thepixel electrode with a driving voltage for driving the liquid crystallayer, the array substrate being disposed so as to face the substrate; aconnection means having a function of electrical connection and afunction of fixed connection, the connection means electricallyconnecting the pixel electrode and the driving electrode, and fixedlyconnecting the display layer and the array substrate.

According to the liquid crystal display device, the display layercomprising the liquid crystal layer is fixedly connected to the arraysubstrate having a non-linear element by the connection means, unlikethe conventional liquid crystal display device in which liquid crystallayers are formed on an array substrate comprising a non-linear element.Since the display layer and the array substrate are independent of eachother, even when a display defect is detected in the liquid crystallayer or other components, the array substrate having the non-linearelement does not have to be abandoned. As a result, a liquid crystaldisplay device with an improved yield is realized at a low cost.

Furthermore, in the liquid crystal display device, the connection meanselectrically connects the pixel electrode on the display layer to thedriving electrode which is connected to the non-linear element. Sincethe two-dimensional relative position of the pixel electrode and thedriving electrode may be within a range of their being connected by theconnection means, the positional precision does not have to be so high.The fixed connection between the array substrate and the display layerby the connection means is performed by bonding, heat depositing,pressing, or the like.

In the liquid crystal display device, the connection means can be madeof an anisotropic conductive adhesive material.

The use of the anisotropic conductive adhesive as the connection meansenables the pixel electrode on the display layer to be electricallyconnected with the driving electrode on the array substrate, andprevents the anisotropic conductive adhesive from short circuitingbecause it is conductive only in the thickness direction.

The liquid crystal display device comprises:

a display layer being composed of a liquid crystal layer formed betweena substrate and a sealing plate by sealing liquid crystal thereinto, thesealing plate being supported by a supporting member arranged betweenthe substrate and the sealing plate; and an array substrate having anon-linear element for supplying the liquid crystal layer with anelectric field so as to light-control drive the liquid crystal layer,the array substrate being disposed so as to face the substrate, whereinthe display layer comprises at least two liquid crystal layers; a firstliquid crystal layer being formed between a common electrode formed onan internal surface of the substrate and a first sealing plate bysealing liquid crystal thereinto, the first sealing plate beingsupported by a first supporting member arranged on the common electrodeand having a first pixel electrode on a surface thereof opposite thecommon electrode; and a second liquid crystal layer being formed betweenthe first sealing plate and a second sealing plate by sealing liquidcrystal thereinto, the second sealing plate being supported by a secondsupporting member arranged on the first sealing plate and having asecond pixel electrode formed on a surface thereof opposite the firstpixel electrode; the array substrate comprises at least two drivingelectrodes and at least two non-linear elements; a first drivingelectrode for supplying the first pixel electrode with a driving voltagefor driving the first liquid crystal layer; a first non-linear elementelectrically connected with the first driving electrode; a seconddriving electrode for supplying the second pixel electrode with adriving voltage for driving the second liquid crystal layer; and asecond non-linear element electrically connected with the second drivingelectrode; wherein the liquid crystal display device further comprises afirst connection means and a second connection means each having afunction of electric connection and a function of fixed connection; afirst connection terminal is electrically connected with the firstdriving electrode via the first connection means; a second connectionterminal is electrically connected with the second driving electrode viathe second connection means; and the display layer and the arraysubstrate are fixedly connected via the first connection means and thesecond connection means.

As a result, a liquid crystal display device which can display colorimages is achieved. The fixed connection between the array substrate andthe display layer by the first and second connection means is performedby bonding, heat depositing, pressing, or the like.

The liquid crystal display device comprises:

a display layer being composed of a liquid crystal layer formed betweena substrate and a sealing plate by sealing liquid crystal thereinto, thesealing plate being supported by a supporting member arranged betweenthe substrate and the sealing plate; and an array substrate having anon-linear element for supplying the liquid crystal layer with anelectric field so as to light-control drive the liquid crystal layer,the array substrate being disposed so as to face the substrate, whereinthe display layer comprises: a first liquid crystal layer being formedbetween a common electrode formed on an internal surface of thesubstrate and a first sealing plate by sealing liquid crystal thereinto,the first sealing plate being supported by a first supporting memberarranged on the substrate and having a first pixel electrode on asurface thereof opposite the common electrode; a second liquid crystallayer being formed between the first sealing plate and a second sealingplate by sealing liquid crystal thereinto, the second sealing platebeing supported by a second supporting member arranged on the firstsealing plate and having a second pixel electrode formed on a surfacethereof opposite the first pixel electrode; and a third liquid crystallayer being formed between the second sealing plate and a third sealingplate by sealing liquid crystal thereinto, the third sealing plate beingsupported by a third supporting member arranged on the second sealingplate and having a third pixel electrode formed on a surface thereofopposite the second pixel electrode; the first pixel electrode iselectrically connected with a first connection terminal; the secondpixel electrode is electrically connected with a second connectionterminal; and the third pixel electrode is electrically connected with athird connection terminal; the array substrate comprises: a firstdriving electrode for supplying the first pixel electrode with a drivingvoltage for driving the first liquid crystal layer; a first non-linearelement electrically connected with the first driving electrode; asecond driving electrode for supplying the second pixel electrode with adriving voltage for driving the second liquid crystal layer; a secondnon-linear element electrically connected with the second drivingelectrode; a third driving electrode for supplying the third pixelelectrode with a driving voltage for driving the third liquid crystallayer; and a third non-linear element electrically connected with thethird driving electrode; the liquid crystal display device furthercomprising a first connection means, a second connection means, and athird connection means each having a function of electrical connectionand a function of fixed connection, wherein the first connectionterminal and the first driving electrode are electrically connected viathe first connection means; the second connection terminal and thesecond driving electrode are electrically connected via the secondconnection means; the third connection terminal and the third drivingelectrode are electrically connected via the third connection means; andthe display layer and the array substrate are fixedly connected via thefirst connection means, the second connection means, and the thirdconnection means.

In the liquid crystal display device, the liquid crystal composing thefirst liquid crystal layer, the second crystal layer, and the thirdliquid crystal layer is guest host liquid crystal containing liquidcrystal and a dichroic dye having a color of cyan, magenta, or yellow,each dichroic dye having a different color from remaining dichroic dyes.

As a result, a liquid crystal display device which can display colorimages is achieved. The fixed connection between the array substrate andthe display layer by the first-third connection means is performed bybonding, heat depositing, pressing, or the like.

The liquid crystal display device comprises: a display layer composed ofa liquid crystal layer formed between a substrate and a sealing plate bysealing liquid crystal thereinto, the substrate having a commonelectrode on an internal surface thereof and the sealing plate beingsupported by a supporting member arranged on the common electrode; andan array substrate having a driving circuit for driving the liquidcrystal layer and a plurality of pixel electrodes arranged atpredetermined intervals and electrically connected to the drivingcircuit, the array substrate being disposed so as to face the substrate;and a connection means for connecting the display layer with the arraysubstrate.

Since the array substrate has the pixel electrodes thereon and thedisplay layer has the common electrode and the liquid crystal layer,different display patterns can be achieved only by changing theformation pattern of the pixel electrodes. Thus, the display layer canbe applied to various array substrates having different display patternsdepending on the uses. The general versatility of the display layer alsorealizes a cost reduction.

In bonding the display layer to the driving substrate, their relativeposition in a plane can be arbitrary. Since alignment is unnecessary,assembly is simplified.

In the liquid crystal display device, the sealing plate can be made of apolymer resin whose thickness is in a range of 0.5 to 10 μm inclusive.

By making the thickness of the sealing plate 0.5 μm or larger, theliquid crystal layer is prevented from having concave and convexportions, and the gap of the liquid crystal layer has a uniformthickness. By making the thickness of the sealing plate 10 μm or below,it becomes unnecessary to provide the pixel electrodes on a side of thesealing plate opposite to the sealing surface. As a result, the liquidcrystal layer can be driven with a low voltage.

In the liquid crystal display device, the substrate and the arraysubstrate can be made of a polymer resin.

The obtained liquid crystal display device is thin and light in weightand defies bending and other deformation.

The liquid crystal display device comprises: a display layer comprisinga liquid crystal layer and a plurality of pixel electrodes, the liquidcrystal layer being formed between a substrate and a sealing plate bysealing liquid crystal thereinto, the substrate having a commonelectrode on an internal surface thereof and the sealing plate beingsupported by a supporting member arranged on the common electrode, andthe plurality of pixel electrodes being arranged at regular intervals ona surface of the sealing plate, the surface being opposite thesupporting member; a plurality of array substrates having a plurality ofnon-linear elements for driving the liquid crystal layer; and aconnection means for connecting the display layer with the plurality ofarray substrates so as to electrically connect the plurality of pixelelectrodes and the plurality of non-linear elements.

In the conventional multi-screen LCD, the pitch of the pixel electrodebecomes uneven at the joints of panels, so that the joints arenoticeable in the display screen. However, in the above structure, theplurality of pixel electrodes are arranged at regular intervals on asurface of the sealing plate adjacent to the array substrates, so thatthe joints between the array substrates do not appear on the displayscreen. As a result, a multi-screen liquid crystal display device withunnoticeable panel joints is realized.

In the liquid crystal display device, the plurality of array substratescan be arranged in a same plane; and the display layer can face theplurality of array substrates within a range of each of the plurality ofpixel electrodes being electrically connected to a corresponding one ofthe plurality of non-linear elements via the connection means.

The structure makes it unnecessary to arrange the array substrates soprecisely as to make the joints between adjacent panels unnoticeable inbonding the display layer to the plurality of array substrates. In otherwords, the two-dimensional relative position of the display layer andthe array substrates may be within a range that the pixel electrodes andthe non-linear elements are electrically connected by the connectionmeans. As a result, requirements for the positional precision can bederogated.

Furthermore, it is unnecessary to increase the pixel pitch in order tomake the panel joints unnoticeable because of the above-mentionedreasons. As a result, a multi-screen liquid crystal display device whichdisplays high precision images is realized.

In the liquid crystal display device, an optical color filter layer canbe disposed between the substrate and the common electrode.

As a result, a liquid crystal display device which can display colorimages is achieved.

The method for fabricating a liquid crystal display device comprises adisplay layer composed of a substrate, a sealing plate, and a liquidcrystal layer disposed therebetween, and an array substrate having adriving element for driving the liquid crystal layer, the methodcomprising the steps of: forming the display layer comprising the substeps of: forming a common electrode on an internal surface of thesubstrate; forming a supporting member onto the common electrode;forming the sealing plate so as to be supported by the supportingmember; forming the liquid crystal layer by sealing liquid crystal intobetween the substrate and the sealing plate; and forming a pixelelectrode on a surface of the sealing plate, the surface being oppositethe liquid crystal layer; providing the array substrate with the drivingelement and a driving electrode; and electrically connecting the pixelelectrode and the driving electrode via a connection means.

Even when a display defect is detected in the liquid crystal layer orother components, the array substrate having the non-linear element doesnot have to be abandoned. As a result, the fabrication cost is decreasedand the yield is increased.

As the seventh step, the substrate and the array substrate are bonded toeach other so that the pixel electrodes and the driving electrodes canbe electrically connected via the connection means. Since thetwo-dimensional relative position of the pixel electrode and the drivingelectrode may be within a range that their being electrically connectedby the connection means, the requirements for the positional precisioncan be derogated.

In the method for fabricating a liquid crystal display device, at leastone other liquid crystal layer can be formed by conducting the steps of:forming a second supporting member onto the pixel electrode; forming asecond sealing plate so as to be supported by the second supportingmember; forming a second liquid crystal layer by sealing liquid crystalinto between the sealing plate and the second sealing plate; and forminga second pixel electrode on a surface of the second sealing plate, thesurface being opposite the second liquid crystal layer.

The method enables the plurality of liquid crystal layers using verythin sealing plates to be easily stacked, so that a liquid crystaldisplay device which can display color images is achieved.

The method for fabricating a liquid crystal display device comprises: afirst step of forming a common electrode on an internal surface of asubstrate; a second step of forming a supporting member on the commonelectrode; a third step of forming a sealing plate so as to be supportedby the supporting member; a fourth step of forming a liquid crystallayer by sealing liquid crystal into between the substrate and thesealing plate; a fifth step of forming a pixel electrode on a surface ofthe sealing plate, the surface being opposite the liquid crystal layer;a sixth step of examining display conditions by supplying a voltage tothe common electrode and the pixel electrode; a seventh step ofproviding an array substrate with a non-linear element for driving theliquid crystal layer and a driving electrode; and an eighth step ofelectrically connecting the pixel electrode and the driving electrodeonly when a display layer is in excellent display conditions, based onresults of an examination conducted in the sixth step.

Since the display conditions of the display layer is examined before thedisplay layer and the array substrate are connected via the connectionmeans, even when a display defect is detected, the array substratehaving the non-linear element does not have to be abandoned. As aresult, the fabrication cost is decreased and the yield is increased.

The method for fabricating a liquid crystal display device comprises: afirst step of forming a common electrode on a surface of a substrate; asecond step of forming a supporting member on the common electrode; athird step of forming a sealing plate so as to be supported by thesupporting member; a fourth step of forming a liquid crystal layer bysealing liquid crystal into between the substrate and the sealing plate;a fifth step of forming a pixel electrode on an array substrate so as toface the common electrode; a sixth step of providing the array substratewith a driving circuit for driving the liquid crystal layer; and aseventh step of bonding the array substrate to the substrate with anadhesive material.

Since the array substrate has the pixel electrode thereon and thedisplay layer has the common electrode and the liquid crystal layer, itis unnecessary to form the display layer in accordance with the patternform of the driving electrode in the driving substrate. Thus, thedisplay layer can be applied to various array substrates havingdifferent display patterns depending on the uses, which realizes adecrease in the fabrication cost. In bonding the display layer to thesubstrate, their relative position in a plane can be arbitrary. Thusalignment is unnecessary, so that assembly is simplified.

The method for fabricating a liquid crystal display device comprises: afirst step of forming a common electrode on a substrate; a second stepof forming a supporting member on the common electrode; a third step offorming a sealing plate so as to be supported by the supporting member;a fourth step of arranging a plurality of pixel electrodes at regularintervals on a surface of the sealing plate, the surface being oppositethe supporting member; a fifth step of forming a liquid crystal layer bysealing liquid crystal into between the substrate and the sealing plate;a sixth step of providing an array substrate with a plurality ofnon-linear elements for driving the liquid crystal layer; a seventh stepof dividing the array substrate into at least two; and an eighth step ofelectrically connecting each of the plurality of pixel electrodes to acorresponding one of the plurality of non-linear elements via aconnection means.

Unlike the conventional liquid crystal display device in which the pixelelectrodes are formed on the display layer side, the plurality of pixelelectrodes are arranged at regular intervals on a surface of the displaylayer opposite to the sealing surface of the sealing plate. Therefore,it is unnecessary to arrange the panels so precisely as to make thedeviation between the measures set before dividing the substrate and themeasures obtained after the substrate is actually divided in order tomake the joints unnoticeable. In other words, since the two-dimensionalrelative position of the display layer and the array substrate may bewithin a range that the pixel electrodes and the non-linear elements areelectrically connected, the requirements for the positional precisioncan be derogated. Furthermore, it is unnecessary to increase the pixelpitch in order to make the panel joints unnoticeable, so that images ofhigh precision are displayed. As a result, a multi-screen liquid crystaldisplay device with unnoticeable panel joins is realized.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects, advantages and features of the invention willbecome apparent from the following description thereof taken inconjunction with the accompanying drawings which illustrate specificembodiments of the invention. In the drawings:

FIG. 1 is a cross sectional view of one pixel in the center of theliquid crystal display device of Embodiment 1-1 of the presentinvention.

FIG. 2 is a plane view of one pixel in the center of the liquid crystaldisplay device of Embodiment 1-1.

FIG. 3 is the entire structure of the liquid crystal display device ofEmbodiment 1-1.

FIG. 4 is a partly magnified cross sectional view of FIG. 1.

FIG. 5 is a partly magnified cross sectional view of FIG. 1.

FIGS. 6(a) and 6(b) are illustrations showing fabrication processes ofthe liquid crystal display device of Embodiment

FIGS. 7(a) and 7(b) are illustrations showing fabrication processes ofthe liquid crystal display device of Embodiment 1-1.

FIG. 8 is an illustration showing a fabrication process of the liquidcrystal display device of Embodiment 1-1.

FIGS. 9(a) and 9(b) are illustrations showing fabrication processes ofthe liquid crystal display device of Embodiment 1-1.

FIGS. 10(a) and 10(b) are illustrations showing fabrication processes ofthe liquid crystal display device of Embodiment 1-1.

FIGS. 11(a) and 11(b) are illustrations showing fabrication processes ofthe liquid crystal display device of Embodiment 1-1.

FIG. 12 is an illustration showing a fabrication process of the liquidcrystal display device of Embodiment 1-1.

FIG. 13 is an illustration showing a fabrication process of the liquidcrystal display device of Embodiment 1-1.

FIG. 14 is a cross sectional view of the vicinity of the venthole 134.

FIG. 15 is an illustration showing a state of preventing the permeationof the solution by applying a surface tension decreasing treatment tothe venthole 134.

FIG. 16 is a cross sectional view of the vicinity of the venthole 135.

FIG. 17 is a cross sectional view of the vicinity of the venthole 136.

FIG. 18 is a cross sectional view of one pixel in the center of theliquid crystal display device of Embodiment 1-5 of the presentinvention.

FIG. 19 is a partial plane view of the mask 153.

FIG. 20 is an illustration showing surface changes of the resin layer150.

FIG. 21 is a cross sectional view of the main part of the liquid crystaldisplay device of Embodiment 2-1 of the present invention.

FIG. 22 is a cross sectional view taken along the line indicated withthe arrows X—X of FIG. 21.

FIG. 23 is an illustration showing the state of wrinkles generated onthe resin film.

FIGS. 24(a) and 24(b) are illustrations showing fabrication processes ofthe liquid crystal display device of Embodiment 2-1.

FIGS. 25(a) and 25(b) are illustrations showing fabrication processes ofthe liquid crystal display device of Embodiment 2-1.

FIGS. 26(a) and 26(b) are illustrations showing fabrication processes ofthe liquid crystal display device of Embodiment 2-1.

FIG. 27 is an illustration showing a fabrication process of the liquidcrystal display device of Embodiment 2-1.

FIG. 28 is a cross sectional view of the main part of the liquid crystaldisplay device of Embodiment 2-2 of the present invention.

FIGS. 29(a) and 29(b) are illustrations showing fabrication processes ofthe liquid crystal display device of Embodiment 2-3.

FIGS. 30(a) and 30(b) are illustrations showing fabrication processes ofthe liquid crystal display device of Embodiment 2-3.

FIGS. 31(a)-31(d) are illustrations showing fabrication processes of theresin film structure of Embodiment 2-4 of the present invention.

FIGS. 32(a)-32(d) are illustrations showing fabrication processes of theresin film structure of Embodiment 2-5 of the present invention.

FIG. 33 is a cross sectional view of the resin film structure ofEmbodiment 2-6 of the present invention.

FIG. 34 is a partial plane view showing the structure of one pixel ofthe liquid crystal display device of Embodiment 3-1 of the presentinvention.

FIG. 35 is a cross sectional view taken along the line indicated withthe arrows A—A of FIG. 34.

FIGS. 36(a) and 36(b) are illustrations showing fabrication processes ofthe liquid crystal display device of Embodiment 3-1 of the presentinvention.

FIGS. 37(c) and 37(d) are illustrations showing fabrication processes ofthe liquid crystal display device of Embodiment 3-1.

FIGS. 38(e) and 38(f) are illustrations showing fabrication processes ofthe liquid crystal display device of Embodiment 3-1.

FIGS. 39(g) and 39(h) are illustrations showing fabrication processes ofthe liquid crystal display device of Embodiment 3-1.

FIGS. 40(i) and 40(j) are illustrations showing fabrication processes ofthe liquid crystal display device of Embodiment 3-1.

FIG. 41(k) is an illustration showing a fabrication process of theliquid crystal display device of Embodiment 3-1.

FIGS. 42( 1 ) and 42(m) are illustrations showing fabrication processesof the liquid crystal display device of Embodiment 3-1.

FIGS. 43(n) and 43(o) are illustrations showing fabrication processes ofthe liquid crystal display device of Embodiment 3-1.

FIG. 44 is a partial plane view showing the structure of one pixel ofthe liquid crystal display device of Embodiment 3-2 of the presentinvention.

FIG. 45 is a cross sectional view taken along the line indicated withthe arrows B—B of FIG. 44.

FIGS. 46(a) and 46(b) are illustrations showing fabrication processes ofthe liquid crystal display device of Embodiment 3-2.

FIGS. 47(c) and 47(d) are illustrations showing fabrication processes ofthe liquid crystal display device of Embodiment 3-2.

FIGS. 48(e) and 48(f) are illustrations showing fabrication processes ofthe liquid crystal display device of Embodiment 3-2.

FIGS. 49(g) and 49(h) are illustrations showing fabrication processes ofthe liquid crystal display device of Embodiment 3-2.

FIG. 50(i) is an illustration showing a fabrication process of theliquid crystal display device of Embodiment 3-2.

FIG. 51 is a partial plane view showing the structure of one pixel ofthe liquid crystal display device of Embodiment 3-3 of the presentinvention.

FIGS. 52(a) and 52(b) are illustrations showing fabrication processes ofthe liquid crystal display device of Embodiment 3-3.

FIGS. 53(c) and 53(d) are illustrations showing fabrication processes ofthe liquid crystal display device of Embodiment 3-3.

FIGS. 54(e) and 54(f) are illustrations showing fabrication processes ofthe liquid crystal display device of Embodiment 3-3.

FIGS. 55(g) and 55(h) are illustrations showing fabrication processes ofthe liquid crystal display device of Embodiment 3-3.

FIG. 56(i) is an illustration showing a fabrication process of theliquid crystal display device of Embodiment 3-3.

FIGS. 57(j) and 57(k) are illustrations showing fabrication processes ofthe liquid crystal display device of Embodiment 3-3.

FIG. 58 is a partial plane view showing the structure of one pixel ofthe liquid crystal display device of Embodiment 3-4 of the presentinvention.

FIG. 59 is a cross sectional view taken along the line indicated withthe arrows C—C of FIG. 58.

FIGS. 60(a) and 60(b) are illustrations showing fabrication processes ofthe liquid crystal display device of Embodiment 3-4.

FIGS. 61(c) and 61(d) are illustrations showing fabrication processes ofthe liquid crystal display device of Embodiment 3-4.

FIGS. 62(e) and 62(f) are illustrations showing fabrication processes ofthe liquid crystal display device of Embodiment 3-4.

FIGS. 63(g) and 63(h) are illustrations showing fabrication processes ofthe liquid crystal display device of Embodiment 3-4.

FIGS. 64(i) and 64(j) are illustrations showing fabrication processes ofthe liquid crystal display device of Embodiment 3-4.

FIG. 65 is a cross sectional view showing the rough structure of theliquid crystal display device of Embodiment 4-1 of the presentinvention.

FIG. 66 is a plane view showing the rough structure of TFT devices inthe liquid crystal display device of Embodiment 4-1.

FIG. 67 is a cross sectional view showing the rough structure of thedisplay unit in the liquid crystal display device of Embodiment 4-1.

FIG. 68 is a cross sectional view showing the rough structure of themain part of the liquid crystal display device of Embodiment 4-1.

FIG. 69 is a cross sectional plane view showing the rough structure ofthe display unit in the liquid crystal display device of Embodiment 4-1.

FIGS. 70(a) and 70(b) are cross sectional views showing the roughstructure of the anisotropic conductive adhesive in the liquid crystaldisplay device of Embodiment 4-1.

FIGS. 71(a) and 71(b) are illustrations showing fabrication processes ofthe liquid crystal display device of Embodiment 4-1.

FIGS. 72(a) and 72(b) are illustrations showing fabrication processes ofthe liquid crystal display device of by Embodiment 4-1.

FIGS. 73(a) and 73(b) are illustrations showing fabrication processes ofthe liquid crystal display device of Embodiment 4-1.

FIGS. 74(a) and 74(b) are illustrations showing fabrication processes ofthe liquid crystal display device of Embodiment 4-1.

FIG. 75 is a cross sectional view showing the rough structure of theliquid crystal display device of Embodiment 4-2 of the presentinvention.

FIG. 76 is an illustration showing a fabrication process of the liquidcrystal display device of Embodiment 4-2.

FIGS. 77(a) and 77(b) are cross sectional views showing the roughstructure of the liquid crystal display device of Embodiment 4-3 of thepresent invention.

FIG. 78 is a plane view showing the rough structure of the arraysubstrate in the liquid crystal display device of Embodiment 4-3.

FIG. 79 is a cross sectional view showing the structure of aconventional liquid crystal display device.

FIG. 80 is a cross sectional view showing the structure of anotherconventional liquid crystal display device.

FIGS. 81(a)-81(c) are illustrations showing examples of inconvenientconditions caused by positional deviation of the supporting members.

FIG. 82 is an illustration showing the pitch conditions of thesupporting members.

FIG. 83 is a cross sectional view showing the rough structure of aconventional liquid crystal display device.

DETAILED DESCRIPTION OF THE INVENTION Embodiment 1

A first embodiment of the present invention will be described as followsbased on the drawings.

The first embodiment is featured by using a commercially available resinfilm as a sealing plane and bonding the resin film onto supportingmembers. This feature secures the fixing of the resin film onto thesupporting members.

Embodiment 1-1

Embodiment 1-1 of the present invention will be described based on FIGS.1-13. FIG. 1 is a cross sectional view of one pixel in the center of theliquid crystal display device of the present invention, FIG. 2 is aplane view of the pixel, FIG. 3 is the entire structure of the liquidcrystal display device, FIGS. 4 and 5 are partly magnified crosssectional views of FIG. 1, and FIGS. 6(a) and 6(b) through 13 areillustrations showing the fabrication processes of the liquid crystaldisplay device. FIG. 1 is a cross section taken along the line indicatedwith the arrows I—I of FIG. 2. FIGS. 1-13 are simplified illustrationsnot showing all the components of the liquid crystal display device, andare different from the actual device in the reduced scales and thenumber of some components.

The liquid crystal display device, as shown in FIG. 1, comprises threeliquid crystal layers 106, 107, and 108 filled with guest host liquidcrystals 121, 122, and 123 of cyan, magenta, and yellow, respectively,which are arranged in that order on a substrate 101. The substrate 101,which is made of borosilicate glass, is provided with thin filmtransistors (hereinafter TFT devices) 102, 103, and 104 made ofamorphous silicon as driving elements thereon. As shown in FIG. 3, thesubstrate 101 is further provided with a first pixel electrode M1arranged in the form of matrix in a pixel display region 145, sourcelines SL, gate lines GL, a driving circuit 180 arranged in a peripheralpart 146 of the pixel display region 145 so as to supply a drivingvoltage to the source lines SL, and a driving circuit 181 arranged inthe peripheral part 146 so as to supply a driving voltage to the gatelines GL.

The TFT devices 103 and 104 respectively have drain terminals 103 a and104 a which are transparent conductive films made of an indium-tin oxide(ITO), whereas the TFT device 102 has a drain terminal 102 aelectrically connected with the first pixel electrode M1 which is atransparent conductive film. Light shielding films 105 each being asquare of 5 μm×5 μm are scattered in the pixel part on the substrate101. The light shielding films 105 has a 30 μm pitch. Supporting members118 are formed on the light shielding films 105 as shown in FIG. 4. Asshown in FIG. 5 the TFT devices 103 and 104 are provided with the lightshielding films 105 on which cubic interconnection pads 140 are formed.The cubic interconnection pads 140 also serve as supporting members. Thelight shielding films 105 are composed of a resist containing blackcarbon particles. The supporting members 118 and the cubicinterconnection pads 140 are composed of 5 μm-high positive type resist.A resin film 111 is bonded onto the supporting members 118 and the cubicinterconnection pads 140 with an adhesive layer 131 made from a positivetype resist provided therebetween. The resin film 111 is 1.2 μm thickand contains polyethylene terephthalate (PET) as a main component whichis a kind of polyester resin. The resin film 111 is supported by thesupporting members 118 so as to form a gap of 5 μm to seal liquidcrystal thereinto between the resin film 111 and the substrate 101. Thegap is filled with a guest host liquid crystal 121 containing a dichroicdye of cyan dissolved in a fluoric nematic liquid crystal, so as to formthe first liquid crystal layer 106.

Above the drain terminals 103 a and 104 a of the TFT devices 103 and104, the cubic interconnection pads 140 and the resin film 111 areprovided with opening portions 124 and 125, respectively. The secondpixel electrode M2, which is an ITO transparent conductive film isformed in the pixel part on the resin film 111. As shown in FIG. 5 anend of the second pixel electrode M2 extends as far as the drainterminal 103 a of the TFT device 103 along the opening portion 124, soas to electrically connect the second pixel electrode M2 and theterminal 103 a. This connection of the second pixel electrode M2 on theresin film 111 with the terminal 103 a of the TFT device 103 on thesubstrate 101 via the opening portion 124 makes it possible to controlthe potential of the second pixel electrode M2 on the resin film 111with the TFT device 103 on the substrate 101.

Above the first liquid crystal layer 106, the second liquid crystallayer 107, a resin film 112, the third liquid crystal layer 108, and aresin film 113 are stacked in that order. As a result, the three liquidcrystal layers 106, 107, and 108 and the three resin films 111, 112, and113 are stacked alternately on the substrate 101. The second and thirdliquid crystal layers 107 and 108 have basically the same structure asthe first liquid crystal layer 106. For the second liquid crystal layer107 comprises supporting members 119, cubic interconnection pads 141,and an adhesive layer 132 whereas the third liquid crystal layer 109comprises supporting members 120, cubic interconnection pads 142 and anadhesive layer 133. The supporting members 118-120 are made of the samematerial and have the same form. The supporting members 119 and 120 arepositioned on an extension line of the supporting members 118. Asdescribed in Japanese Laid-open Patent Application No. 10-70069 earlierfiled by the inventors of the present invention, the structure enablesthe supporting members to firmly support the resin films, so as toprevent the deformation of the supporting members or the damage of theliquid crystal layers due to the misalignment of the supporting members.

The cubic interconnection pads 141 are positioned right above the cubicinterconnection pads 140, and the cubic interconnection pads 142 arepositioned right above the cubic interconnection pads 141. The resinfilms 112 and 113 are made of the same material and have the samethickness as the resin film 111.

The liquid crystal 122 composing the second liquid crystal layer 107 isa guest host liquid crystal having a dichroic dye of magenta, and theliquid crystal 123 composing the third liquid crystal layer 108 is aguest host liquid crystal having a dichroic dye of yellow. In the otherrespects, the second and third liquid crystal layers 107 and 108 areequal to the first liquid crystal layer 106.

An opening portion 125 is formed in the cubic interconnection pads 141and the resin film 112 provided above the drain terminal 104 a of theTFT device 104. A third pixel electrode M3, which is a transparentconductive film is formed in the pixel part on the resin film 112. Asshown in FIG. 5 the third pixel electrode M3 is electrically connectedwith the drain terminal 104 a of the TFT device 104 via the openingportion 125. Similar to the second pixel electrode M2, the structureenables the potential of the third pixel electrode M3 on the resin film111 to be controlled by the TFT device 104 on the substrate 101.

A common electrode 116, which is made of aluminum and also serves as areflective film is formed on the resin film 113 above the third liquidcrystal layer 108. The common electrode 116 is covered with a protectionfilm 117 for protecting the liquid crystal layers from external pressureor the like. The protection film 117 is an acrylic resin. The liquidcrystal layers 121, 122, and 123 each have a dichroic dye of cyan,magenta, and yellow whose concentrations are adjusted by taking colorbalance into consideration.

The liquid crystal display device of the present embodiment has an openarea ratio of 97% or higher in the pixel part (the ratio of the area ofpixels excluding the area for the supporting members to the entire areaof the pixels), which is enough to provide bright display.

The operation of the liquid crystal display device of the presentembodiment will be described as follows. The liquid crystal displaydevice of the present embodiment is a reflective type color liquidcrystal display which achieves color display by the reflection ofexternal light without a back light. The light which is incident uponthe substrate 101 from the side opposite to the liquid crystal layersgoes through the liquid crystal layers 106, 107, and 108 in that orderto be reflected by the common electrode 116 which also serves as thereflective film, and goes back through the liquid crystal layers 108,107, and 106 in that order, thereby providing a display to the observerwho is watching the display from the opposite side of the substrate 101.The liquid crystal layers 106, 107, and 108 are each filled with a guesthost liquid crystal containing a dichroic dye of cyan, magenta, andyellow, respectively. When no voltage is supplied to the pixelelectrodes, each color light of the incident light is absorbed in acorresponding one of the liquid crystal layers, whereas when a voltageis supplied, the incident light permeates these liquid crystal layers.To control the voltage supplied to the liquid crystal layers in thismanner enables the absorption and permeation of light to be controlled,thereby achieving a full-color display.

A specific method for driving the liquid crystal display device of thepresent embodiment will be described as follows. The third pixelelectrode M3 is supplied with voltage V3 in accordance with the imagesignal for the third liquid crystal layer 108 by using the potential ofthe common electrode 116 as a reference potential. The second pixelelectrode M2 is supplied with voltage V2 in accordance with the imagesignal for the second liquid crystal layer 107 by using the potential ofthe third pixel electrode M3 as a reference potential. The first pixelelectrode M1 is supplied with voltage V1 in accordance with the imagesignal for the first liquid crystal layer 106 by using the potential ofthe second pixel electrode M2 as a reference potential. In other words,when the potential of the common electrode 116 is used as a referencepotential, the pixel electrodes M3, M2, and M1 are supplied withvoltages of V3, V3+V2, and V3+V2+V1, respectively. Consequently, each ofthe guest host liquid crystals 123, 122, and 121 can be supplied with avoltage separately.

When alternating driving is conducted in order to prevent deteriorationof the guest host liquid crystals 123, 122, and 121, voltages of (±V3),(±V3)+(±V2), and (±V3)+(±V2)+(±V1) where V1, V2, and V3 are positive canbe supplied. In order to reduce the output voltage of the drivingcircuit or the like by decreasing the absolute value of the supplyvoltage, voltages of (±V3), (±V3)−(±V2), and (±V3)−(±V2)+(±V1) can besupplied by reversing the polarities of the supply voltages of adjacentones of the third-first liquid crystal layers 108, 107, and 106.

Since color image display is performed by the subtractive process, whenthe image signal is given by image data of RGB (red, green, blue), theyare converted to image data of CMY (cyan, magenta, yellow) throughcomplement calculation, and voltages corresponding to these image datacan be supplied. To be more specific, in the case of eight-colordisplay, when the given RGB data is (1, 0, 0), a voltage correspondingto its complement (0, 1, 1) can be supplied.

In the liquid crystal display device of the present embodiment, theresin films and the cubic interconnection pads are provided with openingportions via which the pixel electrodes on the resin films areelectrically connected with the terminals of the TFT devices on thesubstrate. This structure enables the voltage supplied to each pixelelectrode to be controlled by a TFT device on the substrate 101, whichmakes it unnecessary to arrange glass substrates each having a TFTdevice between adjacent liquid crystal layers. As a result, a reflectivetype color liquid crystal display device with bright display and noparallax problem can be achieved. Although TFT devices are used as pixelswitching elements in the present embodiment, thin film diodes or thelike can be used instead.

In the present embodiment, the resin films 111, 112, and 113 are 1.2 μmthick. The resin films are preferably thinner in order to make a voltagedrop small and to reduce the supply voltage. However, when the resinfilms are thinner than 0.5 μm, they become hard to handle because theyare likely to wrinkle or break, so as to decrease the yield.Consequently, it is appropriate that the resin films have a thickness of0.5 μm or larger. On the other hand, when the thickness is larger than10 μm, the resin films have a voltage drop which is larger than twicethe voltage supplied to the liquid crystal layers, so that the voltagerequired to operate the liquid crystal layers becomes very large.Consequently, the resin films are preferably 10 μm or thinner. As aresult, the thickness of the resin films is best set in the range of 0.5to 10 μm.

It is preferable to make the resistivity of the resin films smallerbecause it can reduce the voltage drop in the resin films. Liquidcrystal has different relative permittivity depending on the directionof the alignment. In the case of general liquid crystal whose dielectricanisotropy is positive, when a voltage is supplied between electrodes,molecules are aligned in the direction vertical to the electrodes,thereby increasing the relative permittivity. In particular, in a liquidcrystal material with a small operational voltage, the relativepermittivity becomes ε⊥=4 or so and ε//=11 or so, showing the tendencyof increasing the difference. Since the polyester resin composing theresin films has a relative permittivity of about 3, it might be causedthat when the relative permittivity of the liquid crystal is increasedby the supply of a voltage, more voltage is supplied to the resin filmshaving a smaller permittivity than the liquid crystal, which decreasesthe voltage to be supplied to the liquid crystal. Thus, the voltage dropin the resin films particularly during the supply of a voltage can bereduced by decreasing the resistivity of the resin films. A polyesterresin which is the material for the resin films generally hasresistivity in the range of 10¹⁴ to 10¹⁶. When the resistivity isdecreased to around 10¹², the partial pressure ratio of the resin filmschanges little, showing minor effects of reducing the resistivity,whereas the resistivity is around 10¹⁰ or below, the partial pressureratio of the resin films becomes small. By setting the resistivity at10¹⁰ or below, the voltage drop in the resin films can be reduced toabout half the voltage supplied between the electrodes when the resinfilms have a thickness of 0.5 to 10 μm. Therefore, the resistivity ofthe resin films is preferably 10¹⁰ or below.

In order to reduce the resistivity, the resin films can be mixed with ordoped with a material, namely, a zirconium oxide or an organicconductive member which slightly increases the conductivity.

In the present embodiment, the use of PET (polyethylene terephthalate),which is a kind of polyester as the material for the resin films 111,112, and 113 can provide the resin films with enough strength even whentheir thickness is in the range of 0.5 to 10 μm. In the process ofbonding the resin films to the substrate, which will be described below,the resin films are unlikely to be broken by the pressure of the rollerswhile passing the laminator, which improves the fabrication yield. SincePET is unlikely to plasticize at the heating temperature (150° C.) inthe bonding process, it never happens that the resin films deform alongthe supporting members and narrow the gap to seal liquid crystalthereinto as in the prior art. As a result, it is realized that theresin films are bonded to the substrate smoothly. Since the polyesterresin is transparent and causes a minor light attenuation in the visiblelight wavelength range, bright display is realized. Besides PET used inthe present embodiment, polyethylene naphthalate (PEN) and otherpolyester resins can be used.

In the present embodiment each of the supporting members arranged in thepixel part has a square cross section. The smaller the area occupied bythe supporting members in the pixel part, the higher the open area ratioof the liquid crystal display device becomes, and as a result, brightdisplay is realized. Therefore, from the view point of display, it ispreferable that the width of the supporting members, that is, the lengthof each side of the square cross section is as small as possible, andthe distance between adjacent supporting members is as long as possible.However, the supporting members with a small width are easily crushedand broken in the process of bonding the resin films onto the substrate,making it impossible to seal liquid crystal into the gaps betweenadjacent liquid crystal layers. This inconvenience leads to a decreasein the fabrication yield. When the positive-type resist of thesupporting members is sufficiently hardened, their width can be madelarger than their height so as to prevent the supporting members frombreaking. Since the supporting members have a height of 5 μm in thepresent embodiment, their width should be larger than 5 μm in order toprevent the breakage of the supporting members and to reduce a decreasein the yield.

In the present embodiment, the distance between adjacent supportingmembers arranged in the pixel part is set at 25 μm (the supportingmembers has a side of 5 μm long and a pitch of 30 μm). A large distancebetween adjacent supporting members would cause the resin films to sagtherebetween, making it impossible to keep the gap between the substrateand the resin film or the gaps between adjacent resin films. Thisresults in unevenness in color or a decrease in the contrast ratio. Onthe other hand, when the distance between adjacent supporting members isset at 100 μm or less, the resin films sag less, thereby making each gaphave even thickness. Consequently, each liquid crystal layer has eventhickness and the unevenness in color or a decrease in the contrastratio due to insufficient thickness of the gaps can be prevented.

In the present embodiment, the resin films 111-113 have the opticalanisotropy or the slow axes in the same direction. The opticalanisotropy of the resin films appears in the direction of the slow axes,that is, in the direction to stretch the resin films in their productionprocess. If the slow axes of the resin films stacked on the substratewere in different directions from each other, the resin films mightabsorb light so as to decrease the brightness of the liquid crystaldisplay device. Therefore, the slow axes of the resin films are made tohave the same direction so as to realize a bright display without lightattenuation resulting from the optical anisotropy of the resin films.

The method for fabricating the above-mentioned liquid crystal displaydevice will be described as follows with reference to FIGS. 6-13. Thefollowing processes will be conducted in a yellow room, which isirradiated by light having a long wavelength not to expose aphotosensitive material such as a positive-type resist.

(1) First, as shown in FIG. 6(a) an ITO transparent conductive film isformed by spattering onto the substrate 101 provided with the TFTdevices 102, 103, and 104. The drain terminals 103 a and 104 a of theTFT devices 103 and 104 and the first pixel electrode M1 are patternedby photolithography and etching. At the same time, the source lines andthe gate lines in the vicinity of the pixel part are made from thetransparent conductive film.

Then, a process of forming a light shielding film 105 is conducted. Anegative-type resist containing carbon is applied onto the substrate 101and a mask exposure and developing are conducted in such a manner thatthe resist is left only on the spots where the supporting members 118and the cubic interconnection pads 140 are provided, so as to arrangethe light shielding film 105 as shown in FIG. 6(b). The light shieldingfilm 105 can be formed by applying photolithography and etching to ametallic thin film such as aluminum.

(2) A process of forming the supporting members 118 is conducted. Afirst positive-type resist is applied by spin coating onto the substrate101 provided with the light shielding film 105 thereon, and thesubstrate 101 applied with the resist is pre-baked. An ultraviolet rayis irradiated from the substrate 101 side, so as to expose the area onthe surface of the substrate 101 excluding the spots where thesupporting members 118 and the cubic interconnection pads 140 areformed, by using the light shielding film 105 as a photo mask. After theexposure, the exposed area of the positive-type resist is developed witha developing solution and post-baked to be hardened. As a result, thesupporting members 118 and the cubic interconnection pads 140 are formedonto the light shielding film 105 as shown in FIG. 7(a).

(3) A process of forming an adhesive layer onto the supporting members118 is conducted. As shown in FIG. 7(a) a second positive-type resistwhich is to be an adhesive layer 131 is applied by spin coat onto thesubstrate 101 having the supporting members 118 thereon, and thesubstrate 101 applied with the resist is pre-baked. In the same manneras in the process (2), an ultraviolet ray is irradiated from thesubstrate 101 side to expose the resist using the light shielding film105 as a photo mask, and the second positive-type resist is developedwith a developing solution. As a result, as shown in FIG. 7(b) an about1 μm-thick adhesive layer 131 is formed on the supporting members 118and the cubic interconnection pads 140.

As in the processes (2) and (3), the adhesive layer 131 can be formedexclusively onto the supporting members 118 and the cubicinterconnection pads 140 by the exposure from the rear surface of thesubstrate 101 with the light shielding film 105 as a photo mask. In thecase where the adhesive layer is formed exclusively onto the supportingmembers by conducting an ordinary mask exposure, it would be necessaryto provide an additional process of mask alignment between the adhesivelayer and the supporting members on the substrate. However, on thesupporting members whose cross sections have such short sides as in thepresent invention, positional deviation of only several μm would causethe adhesive area on the supporting members to be too small, leading toa decrease in the yield. To avoid this, the mask alignment would requireextremely high precision. In contrast, the exposure from the rearsurface of the substrate using the light shielding film as a photo maskenables the adhesive layer 131 to be formed onto the supporting members118 easily and precisely without causing no such inconvenience.

The second positive-type resist used for the adhesive layer 131 is madeof such a material as is hardened after exerting thermoplasticity in theheating process (post-baking process) which follows the developing. Inthe present embodiment, the second positive type resist is post-baked at150° C. at which the adhesive layers 131, 132, and 133 exert theirthermoplastic characteristics, which is lower than the temperature forthe resin films 111, 112, and 113 to exert their thermoplasticcharacteristics. The supporting members 118-120, which are alreadyhardened at this moment, do not exert the thermoplastic characteristicswhen hardened again. As a result, in the bonding process which will bedescribed below, the resin films 111, 112, and 113 can be bonded ontothe supporting members 118,119, and 120, respectively, by making onlythe adhesive layers 131, 132, and 133 exert the thermoplasticcharacteristics. Furthermore, smooth bonding of the resin films 111-113onto the supporting members 118-120 can be obtained without causing theabove-mentioned conventional problem that the gaps between the substrateand the resin films are narrowed by the sag of the resin films.

The resin films and the supporting members to be used in the presentinvention are not limited to those described above. The resin films canbe a material either not having thermoplastic characteristics orexerting its thermoplastic characteristics at a higher temperature thanthe adhesive layers. The supporting members can be a material not havingthermoplastic characteristics, exerting the thermoplasticcharacteristics at a higher temperature than the adhesive layers, orbeing subjected to a hardening treatment before the bonding process.Combinations of the resin films and the supporting members and the useof the adhesive layers having thermoplastic characteristics realizesuccessful bonding of the resin films onto the supporting memberswithout causing the deformation of the resin films along the supportingmembers or the breakage of the supporting members.

In an ordinary liquid crystal display device, a sealing material isapplied around the display region in order to seal a gap so that theleakage of liquid crystal from the gap is prevented. In the presentinvention, on the other hand, instead of applying the sealing material,the adhesive layer 131 is formed not only on the supporting members 118but also on the display region periphery 146 (outside the broken line144 in FIG. 12) on the substrate 101 where the supporting members 118are not formed. This makes it possible for the substrate 101 and theresin film 111 to be tightly bonded to each other in the display regionperiphery 146 in the bonding process. During the exposure in the process(3), a photo mask is arranged on the substrate side so as to shield thedisplay region periphery 146 so that the adhesive layer 131 formed inthe display region periphery 146 is left after the developing. Thisprocess makes it unnecessary to provide an additional process ofapplying a sealing material, thereby simplifying the entire fabricationprocesses.

When the adhesive layer 131 is thus formed throughout the circumferenceof the display region periphery 146, it may be caused that the airsealed in the gap between the substrate 101 and the resin film 111expands so as to break the resin film 111 or the bonding between thesupporting members 118 and the resin film 111 breaks in the processinvolving heating or vacuum evacuation after the bonding process. Toavoid this, it is necessary to provide a venthole for ventilating thegap. In the present embodiment, in order to provide such a venthole, inthe process (3) of forming the adhesive layer, the exposure is conductedby using a photo mask which does not shield a part of the display regionperiphery 146 so as to provide the display region periphery 146 with aportion 134′ (refer to FIGS. 12 and 14) where the adhesive layer 131 isnot formed. The portion 134′ in which the substrate 101 and the resinfilm 111 are not bonded in the following bonding process becomes aventhole 134. As shown in FIG. 12, the venthole 134 consists of a firstpassage 134 a leading outside and a second passage 134 b connected tothe first passage 134 a and having a larger cross section than the firstpassage 134 a. This structure not only prevents the breakage of theresin film 111 but also makes the process of forming the venthole 134 beincluded in the process of forming the adhesive layer 131, whichsimplifies the formation of the venthole 134.

(4) The process of bonding the resin film 111 to the substrate 101provided with the supporting members 118 thereon is conducted as shownin FIG. 8. In FIG. 8 the resin film 111 whose main component is PET isstacked on the surface of the substrate 101 where the supporting members118 and the adhesive layer 131 are provided, and is passed between therollers 126, 127 of the laminator. The surface of at least one of therollers 126 and 127, and preferably the surface of the roller 126 whichis in contact with the resin film 111 is set at 150° C. at which theadhesive layer 131 exerts its thermoplastic characteristics. The rollers126 and 127 sandwich the substrate 101 so as to provide it with auniform pressure of 10 MPa, rotating at the rate of 10 mm/sec. As theresult of bonding the resin film 111 to the substrate 101 having thesupporting members 118 an the adhesive layer 131 thereon and passingthem between the rollers 126 and 127 of the laminator, the adhesivelayer 131 is thermal-joined to the resin film 111 so as to bond theresin film 111 to the supporting members 118. Since the temperature ofthe rollers is not so high as to plasticize the supporting members 118or the resin film 111, the resin film 111 can be smoothly bonded withoutthe deformation of the resin film 111 along the supporting members 118or the breakage of the supporting members 118 while the gapcorresponding to the height of the supporting members 118 is maintainedas shown in FIG. 9(a). The substrate 101 having the resin film 111thereon is baked to harden the adhesive layer 131, thereby firmlybonding the supporting members 118 to the resin film 111. The bakingtemperature must be at least higher than the temperature to harden theadhesive layer 131. When the baking temperature is set at a temperatureto cause the resin film 111 to heat-shrink slightly, the resin film 111sags less between supporting members. In the case of the PET resin filmhaving a thickness of 1.2 μm used in the present embodiment, theappropriate baking temperatures are 200 to 220° C.

Through these processes, the resin film 1111 can be firmly bonded ontothe supporting members 118 while the gap between the substrate 101 andthe resin film 111 is maintained, so as to increase the fabricationyield. Furthermore,the processes of removing the resin film andvaporizing the solid film in the prior art become unnecessary, so thatthe application of the resin film can be facilitated and simplified.

In the bonding process (4), if the resin film 111 folds or wrinkleswhile the substrate 101 and the resin film 111 are passing between therollers 126 and 127, the resin film 111 cannot be smoothly bonded to thesubstrate 101, causing unevenness or defects in display. The resin film111 of the present invention wrinkles particularly easily because it isthin, which results in a decrease in the yield. To solve this problem,the resin film 111 is evenly stretched in the direction of arrow B shownin FIG. 8, while it is passing between the rollers 126 and 127.Consequently, the resin film 111 is applied in a smooth state onto thesubstrate 101.

The rollers of the laminator are usually made of an elastic materialsuch as rubber; however, when the roller 126 positioned closer to theresin film is made of an elastic material, the supporting members 118may encroach into the roller 126 by the pressure of the roller 126 inthe process (4) of passing the substrate 101 and the resin film 111together between the rollers, so as to cause the resin film 111 to curvetowards the substrate 101 and the gap not to be maintained. To avoidthis problem, the roller 126 is made of a stiff material such asstainless steel which is hard enough to make the encroaching strengthsmaller than the elastic deformation of the resin film 111. As a result,the resin film in a smooth state can be bonded to the supporting memberswithout the deformation of the resin film 111 due to the encroach of thesupporting members 118, thereby evening the thickness of the gap to sealthe liquid crystal thereinto.

On the spot in the display region periphery 146 where the adhesive layer131 is not provided in the process (4), the venthole 134 is formed asshown in FIG. 12 by applying the resin film 111. Consequently,inconveniences including the breakage of the resin film 111 caused inthe process involving heating or vacuum evacuation can be prevented.However, it may cause a new problem that in the process of soaking thesubstrate in a resist developing solution in order to form thesupporting members onto the resin film or in the process of soaking thesubstrate in an etching solution in order to pattern the transparentconductive film on the resin film, these solutions flow into the gapthrough the venthole 134. Since it is hard to get the flown solutionsout of the narrow gap, some of the solutions remains in the gap anddisturbs the sealing of liquid crystal into the gap.

(5) In order to solve the problem, a process is conducted whichdecreases the surface tension of the gap between the substrate 101 andthe resin film 111 in the vicinity of the first passage 134 a of theventhole 134. As a treatment to decrease the surface tension, thesurface of the substrate 101 or of the resin film 111 in the vicinity ofthe first passage 134 a is coated with a fluoric coating agent 190(refer to FIG. 14). Without such surface treatment, the contact angle ofwater on the PET surface is about 70 degrees, which allows solutionssuch as water to flow into the gap; however, the treatment can changethe contact angle to 90 degrees or larger so as to prevent the flow ofthe solutions as shown in FIG. 15. This method also makes it unnecessaryto open and close the venthole repeatedly when the process of heating orvacuum evacuation and the process of soaking the substrate in thesolution are repeated, thereby simplifying the fabrication processes.

(6) A process of forming opening portions 124 and 125 in the resin film111 bonded to the substrate 101 is conducted. The opening portions 124and 125 are provided in order to electrically connect the pixelelectrodes on the resin film and the drain terminals of the TFT deviceson the substrate. A third positive-type resist 128 is applied by spincoating over the resin film 111 as shown in FIG. 9(a) and pre-baked. Amask exposure is conducted with a photo mask which makes light beirradiated exclusively upon the area where the opening portions 124 and125 are formed, and then the exposed area is developed with a developingsolution. As a result, a 3 μm-thick resist film 128 is formed on theresin film 111 except for the area where the opening portions 124 and125 are formed as shown in FIG. 9(b). Then, the resin film 111 on thearea for the opening portions is removed by an reactive ion etching(RIE) so that the opening portions 124 and 125 are formed as shown inFIG. 10(a). The RIE accelerates oxygen ions in one direction so as tomake them collide with the surface of the resin film, therebydecomposing and vaporizing the resin molecules of the resin film. Theresin film 111 having PET as its main component is decomposed andremoved by the RIE at the rate of 0.3 μm/min. On the other hand, theresist film 128 mainly composed of an acrylic resin is decomposed andremoved at the same rate of 0.3μ/min. as the resin film. In thisembodiment the resin film 111 on the area for the opening portions 124and 125 is removed by the RIE treatment of 5 minutes, whereas the resistfilm 128 remains by a thickness of 1.5 μm so as to protect the resinfilm 111 formed on the area other than the opening portions 124 and 125.Later, the resist film 128 is removed so as to form the opening portions124 and 125 in the resin film 111 as shown in FIG. 10(b). Thus, the RIEenables the opening portions to be formed in the resin film resistant toorganic solvents such as PET or acid.

Besides the RIE, a plasma asher can be used in order to form openingportions in the resin film.

(7) A process of forming the pixel electrodes on to the resin film 111is conducted as shown in FIG. 11(a). The second pixel electrode M2 isproduced by spattering ITO so as to form an about 0.1 μm-thicktransparent conductive film. At this moment, the opening portions 124and 125 provided in the resin film 111 are also covered with ITO, sothat the drain terminals 103 a and 104 a of the TFT devices 103 and 104on the substrate 101 can be electrically connected with the second pixelelectrode M2 on the resin film 111. Then, the pixel part and the openingportions are covered with the resist and the ITO covered on the otherarea is removed by etching. After this, the resist is removed to patternthe ITO into the form of the second pixel electrode M2. As a result, thepotential of the second pixel electrode M2 can be controlled by the TFTdevice 103 on the substrate 101.

(8) The second liquid crystal layer 107 is produced. The layer 107 isproduced by performing the above-mentioned processes (2)-(7) again.After forming the supporting members 119 onto the resin film 111 in theprocess (2), the adhesive layer 132 is formed onto the supportingmembers 119 in the process (3). In the same manner as the processes (2)and (3), light is irradiated from the substrate 101 side, using thelight shielding film 105 formed in the process (1) as a photo mask. As aresult, the supporting members 119 and the adhesive layer 132 of thesecond liquid crystal layer 107 are formed in the same positions as thesupporting members 118 and the adhesive layer 131 of the first liquidcrystal layer 106. Then, in the process (4) the resin film 112 is bondedto the supporting members 119 so as to form a gap between the resinfilms 111 and 112 to seal liquid crystal thereinto. At this moment, theslow axis of the resin film 112 is made equal to that of the resin film111. In the process (5) the treatment is conducted to reduce the surfacetension in the vicinity of the first passage 135 a of the venthole 135(refer to FIGS. 13 and 16) leading to the gap of the second liquidcrystal layer 107. As shown in FIG. 13 the venthole 135 has the samestructure as the venthole 134 and consists of a first passage 135 aleading outside and a second passage 135 b connected to the firstpassage 135 a and having a larger cross section than the first passage135 a.

After the opening portion 125 is formed in the resin film 112 above thedrain terminal 104 a of the TFT device 104 on the substrate in theprocess (6), the third pixel electrode M3 is formed and connected to thedrain terminal 104 a in the process (7). Thus, as shown in FIG. 11(b)the gap for composing the second liquid crystal 107, the resin film 112,and the third pixel electrode M3 are formed.

(9) The third liquid crystal layer 108 is formed. The layer 108 isformed by performing the processes (2)-(5) again. First, in theprocesses (2) and (3), the supporting members 120 and the adhesive layer133 are formed in the same positions as the supporting members 119 ofthe second liquid crystal layer formed on the resin film 112. In theprocess (4), the resin film 113 is bonded to the supporting members 120so as to form a gap between the resin films 112 and 113 to seal liquidcrystal thereinto. The slow axis of the resin film 113 is made the samedirection as those of the resin films 111 and 112. In the process (5)the treatment is conducted to reduce the surface tension in the vicinityof the first passage 136 a of the venthole 136 (refer to FIGS. 13 and17) leading to the gap of the third liquid crystal layer 108. As shownin FIG. 13 the venthole 136 has the same structure as the venthole 134and consists of a first passage 136 a leading outside and a secondpassage 136 b connected to the first passage 136 a and having a largercross section than the first passage 136 a. The ventholes 134-136 areformed in different positions as shown in FIG. 13.

(10) A process of forming the common electrode 116 onto the resin film113 is conducted. The common electrode 116, which also serves as areflective plate is formed as thick as 0.1 μm by aluminum deposition.

(11) A process of forming the protection film 117 made of an acrylicresin onto the resin film 113 provided with the common electrode 116 isconducted.

(12) A process of implanting liquid crystal in a vacuum is conducted.First, the substrate 101 and the resin films 111, 112, and 113 aredivided along the line C—C shown in FIG. 13 so as to remove the firstpassages 134 a, 135 a, and 136 a having increased surface tension,thereby making the second passages 134 b, 135 b, and 136 b function asthe inlets of the liquid crystal. Then, the structure comprising thesubstrate and the resin films stacked thereonto is put into a vacuumimplanting device together with three liquid crystal holders eachcontaining guest host liquid crystal in which a dichroic dye of cyan,magenta, or yellow is dissolved. After the vacuum evacuation, the secondpassages 134 b, 135 b, and 136 b of the three liquid crystal layers areeach made to be in contact with the surface of the liquid crystal ofeach liquid crystal holder so as to vacuum-implant the guest host liquidcrystal corresponding to each color into the gaps of the three liquidcrystal layers. After these gaps are all filled with the liquidcrystals, the substrate is taken out of the vacuum implanting device,and the three second passages 134 b, 135 b, and 136 b are sealed with anultraviolet curing resin. Thus, the liquid crystals 121-123 are sealedinto the gaps of the first-third liquid crystal layers 106-108.

As a result of these processes, the liquid crystal display device shownin FIG. 1 is completed. The extremely thin resin films are bonded ontothe supporting members, and the liquid crystal layers are formed bysealing liquid crystals into the gaps between the substrate and theresin film and between adjacent resin films. This makes the liquidcrystals makes up a larger proportion of the liquid crystal layers, soas to increase the substantial open area ratio, thereby realizing highcontrast ratio and bright display. Furthermore, the small thickness ofthe resin films enables the liquid crystal display device to be drivenat a low voltage, and not requiring glass substrates can realize brightdisplay without parallax. Although the positive type photo resist isused as the supporting members and the adhesive layers in the presentembodiment, a negative type photo resist may be used instead. In thatcase, instead of providing a light shielding film between the substrateand the supporting members, a reflective film is provided on the areawhere no supporting members are provided and used as a mask in formingthe supporting members and the adhesive layers. Since the reflectivefilm is formed on the substrate, the uppermost resin film has atransparent conductive film thereon as the common electrode.

Embodiment 1-2

In Embodiment 1-1 the adhesive layers are formed exclusively on thesupporting members in the adhesive layer formation process. Instead ofthis process, it is possible to conduct a process of previously coatingthe resin film with an adhesive layer and use it as the adhesive layer.In that case, the adhesive layers can be formed while the resin filmsare being produced, making it unnecessary to conduct a process offorming adhesive layers onto the supporting members, thereby simplifyingthe fabrication processes. In the process of bonding the resin film tothe substrate, the surface of the resin film having the adhesive layerthereon is in contact with the supporting members formed on thesubstrate. The adhesive layer can be provided on both surfaces of theresin film.

The adhesive layers on the resin films are produced by thinly coating apolyester resin film with a resin mainly composed of a polyethyleneresin, a polyurethane resin, or the like exerting its thermoplasticcharacteristics at a lower temperature than the polyester resin. Thethickness of the adhesive layers is made to be ⅕ to {fraction (1/10)} ofthat of the resin films. Such thin adhesive layers can reduce a voltagedecrease caused therein.

The thin adhesive layers are produced as follows. A resin film having athickness of about several μm is coated with a resin which is to be anadhesive layer before it is rolled out to be thinner. This makes theresin film and the adhesive layer thinner at the same ratio as they arebefore being rolled out, so that the obtained adhesive layer can beextremely thin and even.

Embodiment 1-3

In Embodiment 1-1 the ventholes 134-136 are provided to ventilate thegaps between the substrate and the resin film and between adjacent resinfilms in the vicinity of the display part, and the surface tension isincreased in the vicinity of the first passages 134 a-136 a of theventholes in order to prevent the flow of solutions into the gapsthrough the ventholes. In the present embodiment, on the other hand, theflow of the solutions can be avoided by sealing the vicinity of thedisplay part and closing the ventholes. In that case, since the air inthe gaps may expand to break the resin films in the process involvingheating or vacuum evacuation, a part of the sealed display part ispenetrated to form ventholes before the process. The ventholes areclosed after the process involving heating or vacuum evacuation andbefore the process of soaking the substrate in the solution. Theventholes, which are provided in the area other than the pixels in thevicinity of the display part, are each formed by making a hole of 50 μmin diameter in the resin films with a laser beam. The closing of theventholes is done by pressing the ventholes with an iron head heated toaround 200° C. so as to heat-joint the resin films.

Since the formation of the three liquid crystal layers requires torepeat the process of opening and closing the ventholes three times, theventholes are formed in different positions each time. As a result, theliquid crystal display device similar to that of Embodiment 1 isobtained. The ventholes can be closed by using an adhesive tape. In thatcase, the process of opening and closing the ventholes is repeated byapplying and removing the tape, so as to obtain the same effects as inEmbodiment 1. The tape should be resistant to the solutions in which thesubstrate is soaked and preferably has comparatively weak adhesion.

Embodiment 1-4

In Embodiments 1-1 and 1-3, the ventilation of the gaps is realized byproviding ventholes. In the present embodiment, on the other hand,instead of providing ventholes, the resin films 111-113 havebreathability. These resin films allow air to go into and out of thegaps in the process involving heating or vacuum evacuation, whichprevents inconvenience such as the breakage of the resin films due tothe expansion of the air when the films have no breathability, or theflow of the solutions into the gaps in the process of soaking thesubstrate in the solutions. Also, a combination of the use of thebreathable resin films and the formation of the ventholes improves theventilation of the gaps and the effect of preventing the breakage of theresin films. In the case where resin films having breathability andwater vapor permeability are used, oxygen or water in the air may gointo the gaps through the resin films after the liquid crystal displaydevice is completed. As a result, the retention ratio of the liquidcrystal deteriorates thereby decreasing the display performance.However, the deposition of aluminum as the common electrode onto theuppermost resin film as in Embodiment 1-1 can block the permeation ofoxygen or water as a shading film. The process of forming a shading filmbecomes unnecessary, thereby simplifying the fabrication processes. Whenthe resin films are exposed in parts on the surface of the liquidcrystal display device, it is necessary to provide a shading film havingneither breathability nor water vapor permeability onto the uppermostresin film 113 so as to prevent a decrease in display performance.

Embodiment 1-5

In Embodiment 1-1, the reflective film 116 which also serves as thecommon electrode is formed onto the uppermost resin film 113 so as toprovide a reflective plate. Since the reflective film formed on the evenresin film has a specular surface, there is a problem that the lightsource is reflected in the reflective film and disturbs the view of thedisplay, while when the display device is seen from an angle causing noreflection, the display becomes dark. In order to solve the problem, aliquid crystal display device has been proposed in Japanese Laid-openPatent Application No. 4-243226. The liquid crystal display device isprovided with a reflective film which has diffusion due to fine concaveand convex portions formed on its surface. The diffusion is obtained byproviding a resin layer having fine concave and convex portions onto thesubstrate, and further providing a reflective film onto the resin layer.If such a reflective film having fine concave and convex portions isformed on the substrate in the structure of Embodiment 1-1, new problemsmay be caused such as (1) the concave and convex portions on thesubstrate surface prevents keeping the space between the reflective filmand the resin film uniformly and (2) when a back side exposure isconducted to form the supporting members and the adhesive layers, thelight is shielded by the reflective film, so that the supporting membersand the adhesive layers cannot be formed in the same position by using apositive-type photo resist like in Embodiment 1-1.

In view of these problems, the present embodiment provides a resin layer150 having a number of fine concave and convex portions on the uppermostliquid crystal layer or the uppermost resin film 113, and furtherprovides a reflective film 151 on the resin layer 150 as shown in FIG.18. The resin layer 150 is made of a transparent positive type photoresist and the reflective film 151 is formed by depositing aluminum.This structure enables the reflective film formed on the liquid crystallayer to have diffusion, so as to make the display clearer and to solvethe problems. The present invention differs from the above-mentionedJapanese application in that the surface of the reflective film havingconcave and convex portions which faces the resin layer is used as areflective surface, and the display becomes dark when the resin layerabsorbs too much light. Therefore, the resin layer 150 must be made froma transparent material as mentioned above.

The present embodiment makes the reflective film also serve as thecommon electrode, so that when a voltage is supplied between theelectrodes, the resin layer causes a voltage drop, thereby lowering avoltage supplied to the liquid crystal layers. In order to avoid thisproblem, a transparent common electrode may be arranged between theresin film 113 and the resin layer 150. In that case, light may beabsorbed by the common electrode so as to darken the display.

The fabrication processes of the present embodiment will be described asfollows, focusing on the parts different from the embodiment 1-1. Afterconducting the processes (1)-(9) of Embodiment 1-1 in the same manner,the process (10) of forming a reflective film is performed as follows. Apositive type photo resist is applied as thick as 1 μm onto the resinfilm 113. As shown in FIG. 19 a mask exposure and developing areconducted by using a photo mask 153 having a number of fine circularholes 152 and a patterning is conducted. After this, an entire surfaceexposure is conducted in order to make the resist transparent, and thenthe substrate is baked in an oven at 200° C. As the photo resist, amaterial causing heat drips during the baking is used so as to changethe convex portions on the surface of the resin layer from thoseindicated by the full line 154 into the round forms indicated by theimaginary line 155, thereby making the concave and convex form milder.Then, a 0.1 μm-thick reflective film 151 is formed on the surface of theresin layer by aluminum deposition. Liquid crystal is implanted in thesame manner as in the process (12) of Embodiment 1-1 so as to completethe liquid crystal display device shown in FIG. 18. A protection filmmay be provided onto the reflective film by conducting the process (11)of Embodiment 1-1 in the same manner.

Thus, the reflective film having diffusion can be formed onto the liquidcrystal layer, so that a better display is obtained.

As described hereinbefore in the embodiments 1-1 through 1-5, a liquidcrystal display device comprises gaps formed between the substrate andthe resin film and between adjacent resin films so as to seal liquidcrystal thereinto. The liquid crystal display device thus produced hasbright display and a high contrast ratio, without unevenness in colorresulting from the parallax caused when the liquid crystal layers arestacked. Furthermore, since resin films are used as the sealing filmsand the resin films are bonded onto the supporting members via theadhesive layers, the fabrication processes are simplified and thefabrication yield is improved.

Embodiment 2

The first embodiment requires a process of forming contact holes everytime a resin film is stacked, in order to connect the electrode on eachresin film and the connection terminals of the driving elements on thesubstrate. To be more specific, the liquid crystal display device havingthree liquid crystal layers stacked on the substrate requires twiceconducting the process of forming contact holes. In view of this aspect,the present embodiment features a simplified process of forming contactholes. The specific structure will be described based on the followingembodiments.

Embodiment 2-1

FIG. 21 is a cross sectional view of the main part of the liquid crystaldisplay device of the present embodiment, and FIG. 22 is a plane view ofthe same taken along the line indicated with arrows XXII—XXII of FIG.21, and FIG. 21 is a cross sectional view taken along the line XXI—XXIof FIG. 22. FIGS. 21 and 22 show one pixel part in the center of theliquid crystal display device.

The present embodiment is an embodiment of the present invention appliedto a color liquid crystal display device. The color liquid crystaldisplay device comprises three resin films stacked on a substrate andgaps which are formed between the substrate and the lowermost resin filmand between adjacent resin films, and are each filled with a guest hostliquid crystal containing a dichroic dye having a different color fromthe other dichroic dyes.

The specific structure of the liquid crystal display device will bedescribed with reference to FIGS. 21 and 22.

Resin films 202, 203, and 204 are stacked in that order onto a substrate201 in such a manner as to be supported by supporting members 205, 206,and 207, respectively, provided thereunder. Gaps A, B, and C with aheight of 5 μm are formed between the substrate 201 and the resin film202, between the resin films 202 and 203, and between the resin films203 and 204, respectively. The gaps A, B, and C are filled with guesthost liquid crystals 224, 225, and 226 containing a dichroic dye ofcyan, magenta, and yellow, respectively. The resin films 202, 203, and204 are 1 μm thick and mainly composed of polyethylene terephthalate(PET). Other resin films whose main component is not PET can be alsoused.

The supporting members 205, 206, and 207 are a positive type resist andeach consist of a number of pillars whose cross section orthogonal tothe axis is a square (10 μm×10 μm in the present embodiment). Thesupporting members 205, 206, and 207 are arranged so as to bedistributed across the entire pixel part with a fixed pitch, and tomaintain the gaps A, B, and C.

The substrate 201 is a transparent substrate made of glass or the like.The substrate 201 is provided with a pixel electrode 208 patterned in afixed shape and TFT devices 221, 222, and 223 as driving elementsthereon. Wrinkle reduction layers 218, 219, and 220 are provided on theresin films 202, 203, and 204, respectively. Pixel electrodes 209 and210 patterned in a fixed shape are provided on the wrinkle reductionlayers 218 and 219, whereas a common electrode 211 is provided on thewrinkle reduction layer 220. Alignment films 228, 229, and 230 made ofpolyimide are provided on the pixel electrodes 208, 209, and 210,respectively, in order to align the liquid crystals 224, 225, and 226.

The gaps A, B, and C are provided with two cubic interconnection padstrings 241 and 242 for each pixel. The cubic interconnection pad string241 consists of three cubic interconnection pads 241 a, 241 b, and 241 carranged almost at the same position in the direction vertical to thesubstrate 201. The cubic interconnection pad string 242 consists ofthree cubic interconnection pads 242 a, 242 b, and 242 c arranged almostat the same position in the direction vertical to the substrate 201.These cubic interconnection pads 241 a-241 c and 242 a-242 c are pillarseach having a square cross section orthogonal to the axis, and are madefrom a positive type resist just like the supporting members 205, 206,and 207. A contact hole 212 is formed through the cubic interconnectionpads 241 a, 241 b, and 241 c and the resin films 202, 203, and 204.Another contact hole 213 is formed through the cubic interconnectionpads 242 a, 242 b, and 242 c and the resin films 202, 203, and 204. Thecontact terminal 222 a of the TFT device 222 is exposed inside thecontact hole 212, and the contact terminal 223 a of the TFT device 223is exposed inside the contact hole 213. The contact hole 212 has afunction to connect the pixel electrode 209 and the TFT device 222, andthe contact hole 213 has a function to connect the pixel electrode 210and the TFT device 223. The part of the alignment film 229 that isexposed inside the contact hole 212 is removed in order to make a partof the pixel electrode 209 under the alignment film 229 be projected andexposed inside the contact hole 212. The part thus exposed inside thecontact hole 212 of each of the connection terminal 222 a and the pixelelectrode 209 is in contact with a conductive member 214 so that the TFTdevice 222 and the pixel electrode 209 are electrically connected. Inthe same manner, the part of the alignment film 230 that is exposedinside the contact hole 213 is removed in order to make a part of thepixel electrode 210 under the alignment film 230 be projected andexposed inside the contact hole 213. The part thus exposed inside thecontact hole 213 of each of the connection terminal 223 a and the pixelelectrode 210 is in contact with a conductive member 215 so that the TFTdevice 223 and the pixel electrode 210 are electrically connected. Theconnection terminal of the TFT device 221 is connected to the pixelelectrode 208 on the substrate 201. This structure realizes cubicinterconnection with respect to each of the pixel electrodes 208, 209,and 210 and the common electrode 211 arranged in the vertical direction,and makes the connection/interruption of the TFT devices 221, 222, and223 control voltages between the pixel electrodes 208 and 209, betweenthe pixel electrodes 209 and 210, and between the pixel electrode 210and the common electrode 211, so as to achieve a full-color display.

The connection structure inside the contact holes 212 and 213, which isthe main feature of the present invention will be detailed as follows.

Concerning the contact hole 212, the bottom surface of the resin film202 is projected from the internal surface of the contact hole 212towards the center of the diameter, and the bottom surfaces of the resinfilms 203 and 204 arranged above the resin film 202 form a single planewith the internal surface of the contact hole 212. The part of the resinfilm 202 that is projected inside the contact hole 212 has the pixelelectrode 209 thereon, which is exposed inside the contact hole 212. Inorder to obtain the pixel electrode 209 thus exposed, the pixelelectrode 209 is made of an inorganic material (ITO) resistant to dryetching using oxygen plasma or the like, and when dry etching isconducted to form the contact hole 212, the difference in etching ratebetween the pixel electrode and the resin films made of an easily etchedmaterial is used.

The exposure of the pixel electrode 209 inside the contact hole 212makes the conductive member 214 and the pixel electrode 209 be incontact with each other with their surfaces so as to secure theconnection therebetween. Consequently, the reliability of the connectionbetween the pixel electrode 209 and the connection terminal 222 a of theTFT device 222 is improved.

Concerning the contact hole 213, in the same manner as the contact hole212, the resin film 203 and the pixel electrode 210 formed thereon areprojected inside the contact hole 213, so that the pixel electrode 210is exposed inside the contact hole 213 and in contact with theconductive member 215. This structure secures the connection between thepixel electrode 210 and the conductive material 215, thereby improvingthe reliability of the connection between the pixel electrode 210 andthe connection terminal 223 a.

The wrinkle reduction layers 218, 219, and 220, which are anotherfeature of the present embodiment will be described. These wrinklereduction layers 218-220 are 0.2 μm-thick films made from a materialresistant to spattering such as an acrylic resin. In forming theelectrodes, the wrinkle reduction layers made of the acrylic resin areprovided onto the resin films and then ITO is spattered onto the wrinklereduction layers to form inorganic material layers.

The reason of the provision of the wrinkle reduction layers is asfollows. The inventors of the present invention have found a problemthat when an inorganic material such as ITO is directly spattered onto aresin film with a thickness of 10 μm or less, the resin film wrinkles asshown in FIG. 23 by the impact of the spattering. FIG. 23 is a planeview of one pixel when the processes up to the formation of the pixelelectrode 209 onto the substrate 201 are conducted in the fabrication ofthe liquid crystal display device shown in FIG. 21. FIG. 23 roughlycorresponds to FIG. 22, while omitting gate lines, source lines, andother components. As shown in FIG. 23 the resin film 202 on the wholepixel part has wrinkles 250 through the columnar supporting members 205arranged with a 50 μm pitch, which causes the light to be diffused onthe surface of the resin film 202. In order to reduce or preventwrinkles, the wrinkle reduction layers 218, 219, and 220 are provided.As a result, the resin film is formed in a smooth condition as shown inFIGS. 22 and 24(b). Although the wrinkle reduction layers in the presentembodiment are made of an acrylic resin, they may be made of an organicresin containing silica particles to obtain the same effects.

In the present embodiment, an ITO film as the transparent electrode isformed on each resin film. Even when another inorganic material (such asindium oxide zinc) is formed on each resin film, the wrinkling of theresin films can be reduced or prevented by providing the wrinklereduction layers.

The problem of the wrinkling of the resin films is not limited to thecase where gaps are formed between the substrate and the resin film andbetween adjacent resin films and supported by the spacers as in thepresent embodiment. The same problem is caused in the case where theresin film having a thickness of about 10 μm or below is tightlyarranged onto the substrate and an inorganic material is directlyapplied onto the resin film. In that case, the wrinkling can be reducedor prevented by providing the wrinkle reduction layer.

The fabrication processes of the liquid crystal display device havingthe above-mentioned structure will be described with reference to FIGS.24-27 which simplify the fabrication processes seen from the same crosssection as in FIG. 21.

First of all, the alignment film 228 is formed onto the substrate 201provided with the TFT devices 221, 222, and 223 thereon. Then, cubicinterconnection pads 241 a and 242 a made of a positive type resist andcomprising the supporting members 205 and holes 212 a and 213 a(corresponding to parts of the contact holes 212 and 213) are formedonto the alignment film 228. The resin film 202 is applied onto thesupporting members 205 and the pad 241 a and 242 a by using a laminator,so as to make the structure shown in FIG. 24(a). The resin film 202 isbonded to the supporting members 205 and the cubic interconnection pads241 a and 242 a via a very thin adhesive layer of a positive typeresist. In FIG. 24(a) the adhesive layer is included in the supportingmembers 205 and the pads 241 a and 242 a.

As shown in FIG. 24(b) an acrylic resin is applied as thick as 0.2 μmonto the resin film 202 by spin coating and hardened to form the wrinklereduction layer 218. An ITO film is formed as thick as 0.13 μm onto thewrinkle reduction layer 218 by spattering. Thus, the provision of thewrinkle reduction layer prevents the resin film from being wrinkled bythe formation of an ITO film. The ITO film is patterned into the form ofa pixel by photolithography and etching with hydroiodic acid, so as toform the pixel electrode 209. The patterning is conducted so as toremove the ITO film from the area corresponding to the hole 212 b havinga smaller size than the hole 212 a as shown in FIGS. 24(b) and 22 and toleave the vicinity of the hole 212 b. The pixel electrode 209 in thevicinity of the hole 213 a is removed.

After these processes are conducted once more to form the alignment film229, the supporting members 206, and the cubic interconnection pads 241a and 242 b, the resin film 203 is applied thereonto, and the wrinklereduction layer 219 and the pixel electrode 210 are formed. Thepatterning is conducted so as to remove the ITO film from the area ofthe pixel electrode 210 corresponding to the hole 213 b having a smallersize than the hole 213 a as shown in FIGS. 25(a) and to leave thevicinity of the hole 213 b. In the vicinity of the contact hole 212, theITO is removed. By conducting the same processes one more time, thestructure shown in FIG. 25(a) comprising three resin film layers stackedon the substrate is formed. The common electrode 211 is made byspattering ITO in the same manner as the pixel electrode 209, and apatterning is conducted so as to remove the electrodes in the vicinityof the contact holes 212 and 213.

As shown in FIG. 25(b) `a positive type resist 227 is applied as thickas 6 μm, and a mask exposure and developing are conducted so as toremove the resist only from the area of the contact holes 212 and 213.

Then, the contact holes 212 and 213 are formed by the RIE with oxygenplasma which is a kind of dry etching. The resin films, the positivetype resist, the alignment film, and the acrylic resin composing thewrinkle reduction layers are etched by the RIE, whereas the pixelelectrode made from ITO is hardly etched. In the present embodiment, theresin films and the positive type resist are etched at the rate of 1μm-depth per minute with an oxygen flow rate of 15 SCCM and an electricpower of 150 W. When the etching is started from the positive typeresist 227 side of FIG. 25(b), the etching proceeds exclusively on thesurface of the positive type resist 227 and in the contact holes 212 and213. In the contact holes 212 and 213 the wrinkle reduction layer 220and the resin film 204 are removed, which is followed by the removal ofthe alignment film 230, the wrinkle reduction layer 219, and the resinfilm 203. At this moment, in the contact hole 213 after the alignmentfilm 230 is removed, the wrinkle reduction layer and the resin film areremoved exclusively from the internal portion of the hole 213 b formedby removing the pixel electrode 210 by a patterning. Since the part ofthe pixel electrode 210 which is projected inside the contact hole 213is not etched and left together with the underlying resin film 203, thepart of the pixel electrode 210 can be exposed inside the contact hole213. Then, the alignment film 229, the wrinkle reduction layer 218, andthe resin film 202 are removed. The alignment film 229, the wrinklereduction layer 218, and the resin film 202 are removed only from theareas right under the internal area having the same size as the hole 213b.

In the contact hole 212, on the other hand, after the removal of thealignment film 229, the resin film 202 is removed exclusively from theinternal part of the hole 212 b which is formed by removing the pixelelectrode 209 by patterning. The resin film 202 is left without beingetched at the part of the pixel electrode 209 which is projected insidethe contact hole 212, so that the pixel electrode 209 is exposed insidethe contact hole 212. Furthermore, the alignment film 228 over theconnection terminals 222 a and 223 a of the TFT devices is removed, sothat these connection terminals 222 a and 223 a are exposed inside thecontact holes 212 and 213.

By conducting the RIE for 5 minutes, the pixel electrodes 209 and 210and the connection terminals 222 a and 223 a are exposed inside thecontact holes 212 and 213 as shown in FIG. 26(a), and the remainingportions are protected by the positive type resist 227.

The conductive members 214 and 215 made of a water-soluble carbon resinare applied by spin coating as shown in FIG. 26(b). Consequently, thecontact holes 212 and 213 are filled with the conductive members 214 and215. After that, the positive type resist 227 is removed with a removalsolution to make the conductive members applied other than in thecontact holes 212 and 213 are separated together with the positive typeresist 227. As a result, the structure shown in FIG. 27 is formed wherethe conductive members 214 and 215 are sealed exclusively into thecontact holes 212 and 213. Thus, in the contact holes 212 and 213 thepixel electrodes 209 and 210 exposed inside these contact holes are incontact with the conductive members 214 and 215, securing theirconnection with the connection terminals 222 a and 223 a. Consequently,it is secured to control the supply of a voltage onto the pixelelectrodes 209 and 210 by the TFT devices 222 and 223 on the substrate.

As a result of these processes, the contact holes can be formed byconducting the formation process only one time while the electricconnection being secured in the contact holes. Thus, the contact holesformation process can be simplified.

It may be easily understood that the contact holes can be formed in asingle formation process if the process is conducted after all the resinfilms are stacked, thereby simplifying the production processes.However, when the alignment film for aligning liquid crystal is formedonto the substrate, if the resin films provided with electrodes thereonare merely stacked and then the contact holes are formed after that, thepixel electrodes on the resin films are exposed only on the crosssection of the contact holes. When the electrodes are made from ITO, thethickness of the electrodes is often set to be about 0.1 to 0.2 μm fromthe optical characteristics. Therefore, when the contact holes areformed and then provided with conductive members in order to beconnected with electrodes, the electrodes are in contact with theconductive members only at the cross section whose thickness is 0.1 to0.2 μm, which is not sufficient to expect secure connection. Incontrast, the structure of the present embodiment where the pixelelectrodes are projected and exposed inside the contact holes provides alarge area for the pixel electrodes and the conductive members tocontact each other, thereby securing their connection.

Although the pixel electrodes are covered with the alignment film in thepresent embodiment, the pixel electrodes not covered with a resin filmlike the alignment film can be exposed inside the contact holes,providing the same effects.

Embodiment 2-2

FIG. 28 is a cross sectional view of the main part of the liquid crystaldisplay device of Embodiment 2-2. The feature of the present embodimentis that the internal surfaces of the contact holes 212 and 213 havesteps so as to expose the pixel electrodes 209 and 210 inside thecontact holes 212 and 213, respectively. To be more specific, thecontact holes 212 and 213 with steps are formed by making the size ofthe holes 212 b and 212 c of the cubic interconnection pads 241 b and241 c larger than that of the hole 212 a of the cubic interconnectionpad 241 a, and the size of the hole 213 c of the cubic interconnectionpad 242 c larger than that of the holes 213 a and 213 b of the cubicinterconnection pads 242 a and 242 b. This structure enables the pixelelectrodes to be exposed, without being projected together with theresin films like eaves as in Embodiment 2-1. As a result, it becomespossible to form the contact holes by a single formation process as inEmbodiment 2-1 and also to increase the area for the pixel electrodesand the conductive members to be in contact with each other, so as toprovide secure connection.

Embodiment 2-3

In Embodiment 2-1, contact holes are formed by patterning a positivetype resist and conducting the RIE dry etching. In contrast, in thepresent embodiment the contact holes are formed by using a laser toremove the resin films in the form of spots. The method of formingcontact holes according to the present embodiment will be described withreference to FIG. 29.

As shown in FIG. 29(a) in the same manner as Embodiment 2-1, three resinfilms 202, 203, and 204, the pixel electrodes 208, 209, and 210, and thecommon electrode 211 are stacked on the substrate 201 with spacers andthe cubic interconnection pads 241 a-241 c and 242 a-242 c therebetween.Then, as shown in FIG. 29(b) a laser is irradiated upon the spots wherethe contact holes 212 and 213 are formed. The size of the holes 212 dand 213 d formed by removing the resin films with the laser is madesmaller than that of the holes 212 a and 213 a of the cubicinterconnection pads. As a result, like in Embodiment 2-1, the resinfilms 202 and 203 and the pixel electrodes 209 and 210 can be projectedinside the contact holes. However, the pixel electrodes 209 and 210 arenot exposed because they are still covered with the alignment films 229and 230. Therefore, after the formation of the contact holes, beforefilling the conductive members 214 and 215, the contact holes 212 and213 are cleaned with a solution which can dissolve the alignment films229 and 230, so as to expose the electrodes 209 and 210 as shown in FIG.30(a). Then, as shown in FIG. 30(b) the contact holes 212 and 213 arefilled with the conductive members 214 and 215, respectively, so as toconnect the electrodes on the resin films and the conductive members.Since this method enables the contact holes to be formed in theelectrodes on the resin films and in the resin films at the same time,it is unnecessary to remove the electrodes from the spots where thecontact holes are formed, when the electrodes on the resin films arepatterned.

Embodiment 2-4

In Embodiment 2-1 spacers are provided between the substrate and theresin films and between adjacent resin films, and liquid crystal issealed into the gaps. However, in the case where the resin films aremerely stacked without providing such gaps, the cubic interconnection ofthe vertically arranged pixel electrodes can be produced by conductingthe contact holes formation process only once. Although the resin filmsare previously formed into films in Embodiment 2-1, a resin material canbe applied onto the substrate so as to make a film. One such example isshown in the present embodiment.

FIGS. 31(a)-31(d) show production processes of the resin film structureaccording to the present embodiment. The resin film structure can bemade of a multi-layer circuit substrate. First, a resin film 232 isapplied by spin coating onto a substrate 231 provided with an electrode235 thereon. The resin film 232 is made of the same acrylic resin as thewrinkle reduction layers used in Embodiment 2-1. An electrode 236 madeof ITO is formed onto the resin film 232 and patterning is conducted insuch a manner as to remove the portion 239 a which is to be the contacthole 239. The resin films 233 and 234 are further applied by spincoating so as to form the structure shown in FIG. 31(a). After theseresin films are stacked, a positive type resist 240 is applied as shownin FIG. 31(b), and a portion 239 where the contact hole is formed isremoved by mask exposure and developing. Then, the resin films 232, 233,and 234 in the portion 239 for the contact hole are removed by dryetching, so as to expose the electrodes 235 and 236 inside the contacthole, as shown in FIG. 31(c). By filling the contact hole 239 with aconductive member 238 in the same manner as in Embodiment 2-1, theelectrodes 235 and 236 are connected with each other via the conductivemember 238, thereby realizing cubic interconnection.

Embodiment 2-5

FIGS. 32(a)-32(d) show production processes of the resin film structureof Embodiment 2-5. The present embodiment has a feature of connectingelectrodes on different resin films. In other words, the presentembodiment basically has the same structure as Embodiment 2-4, butdiffers in that the electrodes 236 and 237 formed on the resin films 232and 233, respectively, are connected to each other via the conductivemember 238. When the electrodes on the different resin films areconnected to each other, as shown in FIG. 32(a) a portion 239 a on theelectrode 236 which is to be removed to form a contact hole is madesmaller than a portion 239 b on the electrode 237. Thus, larger areasare removed in upper layers. As a result of the positive type resist 240being formed as shown in FIG. 32(b) and the contact hole being formed bydry etching as shown in FIG. 32(c), the electrodes 236 and 237 areexposed in the contact hole 239. When the contact hole 239 is filledwith the conductive member 238 as shown in FIG. 32(d) the electrodes 236and 237 are connected each other via the conductive member 238. Thus,both the electrodes 236 and 237 are exposed inside the contact hole,thereby securing the connection between the electrodes.

Embodiment 2-6

FIG. 33 shows a cross sectional view of the resin film structure ofEmbodiment 2-6. While Embodiments 2-4 and 2-5 connect the electrodeseach other, the present embodiment has a feature of electricallyconnecting driving elements 245 and 246 formed on the substrate 231 withthe electrodes 236 and 237. The resin film structure is produced asfollows. Two contact holes 247 and 248 are formed basically in the samemanner as in Embodiments 2-4 and 2-5. Then, parts of the electrodes 236and 237 are exposed inside the contact holes 247 and 248 so as to beelectrically connected with the connection terminals 245 a and 246 a ofthe driving elements 245 and 246, respectively, via the conductivemembers 249 and 250.

Others

Although the conductive members used for the connection in the contactholes are a carbon paint in Embodiments 2-1 through 2-6, otherconductive materials can be used as well. For example, a metallic filmsuch as electrodeless plating can be applied onto the surface of thecontact holes. In that case, after the formation of the metallic filmonto the contact holes, the positive type resist for protecting theresin film is eliminated so as to remove the metallic film formed otherthan on the contact holes, which brings about the same effects as inEmbodiment 2-1.

Embodiments 2-1 through 2-3 show liquid crystal display devices. Bydisposing a luminophor such as electroluminescence which emits lightwhen there is a voltage supply between the substrate and the resin filmor between adjacent resin films, a display device having multi-layerstructure with improved reliability concerning electric connection canbe obtained.

As shown in Embodiments 2-4 through 2-6, the present invention can beused as something other than display devices. For example, the inventionis used for the construction of cubic interconnection of stacked layersin a circuit substrate with resin films.

As described hereinbefore, Embodiments 2-4 through 2-6 achieve theconnection between the electrodes formed on different resin films in theresin film structure with stacked resin films by conducting the contactholes formation process one time, which secures the connection in thecontact holes.

Furthermore, when a transparent electrode made of an inorganic materialsuch as ITO is formed on the resin films, the resin films are preventedfrom wrinkling, keeping the surfaces in a smooth state. As a result, thecharacteristics of the display devices are not lost.

Embodiment 3

Embodiment 3-1

The liquid crystal display device of Embodiment 3-1 of the presentinvention will be described as follows based on FIGS. 34 through 43.FIG. 34 is a partial plane view showing the structure of one pixel ofthe liquid crystal display device, FIG. 35 is a cross sectional viewtaken along the line indicated with arrows XXXV—XXXV of FIG. 34, andFIGS. 36-43 show the fabrication processes of the liquid crystal displaydevice.

These figures are illustrated in a simplified form with modified scales.The size of each component may be magnified or reduced, and those unitswhich might disturb the understanding of the structure are notillustrated.

First, the structure of the liquid crystal display device will bedescribed based on FIGS. 34 and 35.

As shown in FIGS. 34 and 35 TFT devices 2-4 are formed on a substrate 1made of borosilicate glass. The TFT devices 2-4 comprise semiconductorlayers 2 a-4 a made of amorphous silicon, gate electrodes 2 b-4 b,source electrodes 2 c-4 c, and drain electrodes 2 d-4 d, respectively.The drain electrode 2 d of the TFT device 2 is composed of a part of afirst pixel electrode 9 formed in the region corresponding to the pixelsin the substrate 1.

The first pixel electrode 9 is made of aluminum and serves as areflective film. A black matrix 5 is provided around the first pixelelectrode 9. The black matrix 5, which is made of a resist containingblack carbon particles absorbs light incident upon the region other thanthe first pixel electrode 9 so as to increase the contrast ratio. Thefirst pixel electrode 9 and the black matrix 5 have a number of 7 μm×7μm opening portions 5 a and 9 a each arranged with a 30 μm pitch. Theblack matrix 5 is further provided with opening portions 5 b in thedrain electrodes 3 d and 4 d of the TFT devices and in their vicinity(In FIG. 34 the region of the black matrix 5 is illustrated with dots).

At the positions of the opening portions 9 a, 5 a, and 5 b of the firstpixel electrode 9 and the black matrix 5, supporting members 18 arearranged as spacers. The supporting members are made of a negative typeresist hardened by the exposure via these opening portions 9 a, 5 a, and5 b and have a height of 4 μm and a cross section of 7 μm×7 μm. Asealing plate 11 is provided on the supporting members 18 while beingsupported by the supporting members 18 so as to have a distance of 4 μmfrom the substrate. A liquid crystal layer 21 is provided between thesubstrate 1 and the sealing plate 11. The liquid crystal layer 21 isso-called polymer diffusion type liquid crystal wherein guest hostliquid crystal containing fluoric nematic liquid crystal and cyandichroic dye dissolved therein is held in acrylic polymer network. Sincethe liquid crystal layer 21 is sealed with the sealing plate 11, theamount of the network polymer in the liquid crystal layer 21 does nothave to be larger than fixing the sealing plate 11. Therefore, ascompared with the liquid crystal display device shown in FIG. 79, theliquid crystal makes up a larger proportion of the liquid crystal layer,thereby making the substantial open area ratio larger, so that a highcontrast ratio can be obtained. The sealing plate 11 and the liquidcrystal layer 21 are respectively provided with opening portions 11 aand 21 a for cubic interconnection above the drain electrodes 3 d and 4d of the TFT devices 3 and 4.

The first pixel electrode 9, the liquid crystal layer 21, the supportingmembers 18, and the sealing plate 11 compose a first display layer 6,above which a second display layer 7 and a third display layer 8 arestacked. Similar to the first display layer 6, the second display layer7 is composed of a second pixel electrode 14, a liquid crystal layer 22,supporting members 19, and a sealing plate 12, and the third displaylayer 8 is composed of a third pixel electrode 15, a liquid crystallayer 23, supporting members 20, and a sealing plate 13.

In the second display layer 7 the guest host liquid crystal for theliquid crystal layer 22 has a dichroic dye of magenta. The second pixelelectrode 14 formed in the region corresponding to the pixels on thesealing plate 11 is composed of a transparent conductive film made ofITO in place of aluminum. The second pixel electrode 14 is connectedwith the drain electrode 3 d of the TFT device 3 via the openingportions 11 a and 21 a of the sealing plate 11 and the liquid crystallayer 21. Furthermore, the sealing plate 12 and the liquid crystal layer22 are provided with opening portions 12 a and 22 a for cubicinterconnection only on the position above the drain electrode 4 d ofthe TFT device 4.

On the other hand, the third display layer 8 comprises a yellow dichroicdye contained in the liquid crystal layer 23, and the third pixelelectrode 15 is made of the same transparent conductive film as thesecond pixel electrode 14, and is connected with the drain electrode 4 dof the TFT device 4 via the opening portions 12 a, 22 a, 11 a, and 21 aof the sealing plate 12, the liquid crystal layer 22, the sealing plate11, and the liquid crystal layer 21, respectively. The sealing plate 13and the liquid crystal layer 23 have no opening portions.

Similar to the supporting members 18 of the first display layer 6, thesupporting members 19 and 20 of the second display layer 7 and the thirddisplay layer 8, respectively, are made of a negative type resisthardened by the exposure via the opening portions 9 a, 5 a, and 5 b ofthe first pixel electrode 9 and the black matrix 5. As a result, thesupporting members 19 and 20 are arranged in the exact same position asthe supporting members 18. In the guest host liquid crystal contained inthe liquid crystal layers 21-23 of the display layers 6-8, theconcentration of the dichroic dye of cyan, magenta, and yellow iscontrolled to make an appropriate color balance.

A common electrode 16, which is made of a transparent conductive filmand common to all the pixels is provided on the sealing plate 13 of thethird display layer 8. Also, a protection film 17 made of a transparentresin is formed on the common electrode 16 so as to protect the liquidcrystal display device from external pressure or the like.

In the liquid crystal display device thus structured, the voltages to besupplied to the first to third pixel electrodes 9, 14 and 15 arecontrolled via the TFT devices 2-4, so as to change the voltages betweenthe first pixel electrode 9 and the second pixel electrode 14, betweenthe second pixel electrode 14 and the third pixel electrode 15, andbetween the third pixel electrode 15 and the common electrode 16, thatis, the voltages to be supplied to the liquid crystal layers 21-23.According to the changes, the amount of light of each color absorbed ineach of the display layers 6-8 also changes. The light (external light)incident from the protection film 17 side penetrates the third, second,and first display layers 8, 7, and 6 in that order, and is reflected bythe first pixel electrode 9. Then, while it goes back through the first,second, and third display layers 6, 7, and 8 in that order, each colorlight is absorbed in accordance with the supplied voltage, so as toconduct color display by the subtractive process.

The following is a description on the size, pitch, and open area ratioof the supporting members 18-20 in the above-mentioned liquid crystaldisplay device.

The open area ratio of the liquid crystal display device is the productof the ratio of the area for the pixels to the area for the displayscreen (the open area ratio of the pixels in the display screen) and theratio of the area for the region excluding the supporting members 18-20to the area for the pixels (the open area ratio in the pixels). Sincethe open area ratio of the pixels in the display screen is determined bythe area occupied by the TFT devices 2-4, and their source and gatelines, to increase the entire open area ratio requires increasing theopen area ratio in the pixels. In other words, as the pitch of each ofthe supporting members 18-20 becomes larger and as the size of thesupporting members 18-20 become smaller, the open area ratio can belarger and the contrast ratio can be higher.

However, when the pitch of each of the supporting members 18-20 is 50 μmor larger, the sealing plate 11 bends down between adjacent supportingmembers 18 as shown in FIG. 82, making it difficult to keep the liquidcrystal layer 21 at a fixed thickness. Therefore, in order to keep theliquid crystal layer 21 at a fixed thickness, it is preferable to formthe supporting members 18 at a high density. For example, setting thepitch of the supporting members 18 at 30 μm enables the liquid crystallayer 21 to have a fixed thickness, so as to obtain a high open arearatio.

In the case where the alignment precision of the supporting members18-20 is low, the size of the supporting members 18-20 must be increasedin order to prevent the inconvenience shown in FIGS. 81(a)-81(c). Whenthe supporting members 18 have a square cross section of 10 μm×10 μm,their area accounts for 10% or more of the pixel area, so that the openarea ratio in the pixels is reduced and the contrast ratio is decreased.In contrast, in the present embodiment the supporting members 18-20 ofthe display layers 6-8 are made of a negative type resist hardened bythe exposure through the opening portions 9 a, 5 a, and 5 b of the firstpixel electrode 9 and the black matrix 5, so that the supporting members18-20 are arranged in the exact same positions, not causing theabove-mentioned inconvenience. This makes it possible to reduce thecross section of the supporting members 18-20 to a square of 7 μm×7 μmor so, thereby obtaining a 95% or higher open area ratio in the pixels.Since the liquid crystal layers 21-23 contain polymer network, thesubstantial open area ratio becomes slightly smaller than this.

The method for fabricating the above-mentioned liquid crystal displaydevice will be described as follows based on FIGS. 36 through 43.

The following fabrication processes are mainly conducted in a yellowroom irradiated by light having a long wavelength which does not exposea photosensitive material such as a negative type resist in order toprevent unnecessary exposure.

(1) As shown in FIG. 36(a) the TFT devices 2-4 made of amorphous siliconare formed onto the substrate 1 made of borosilicate glass. Then, analuminum reflective film is formed by vacuum deposition and patternedinto the form of pixel by photolithography and etching, so as to producethe first pixel electrode 9 which serves both as the reflective film andthe drain electrode 2 d of the TFT device 2. In the patterning, theopening portions 9 a are also formed.

(2) As shown in FIG. 36(b) after a carbon-contained positive type resistis applied as thick as 1 μm, mask exposure and developing are conductedto the region for the first pixel electrode 9 and to the region for theopening portions 5 a and 5 b so as to form a black matrix 5 having theopening portions 5 a and 5 b.

Then, the supporting members 18 are formed by the following processes(3)-(5).

(3) As shown in FIG. 37(c) after a negative-type resist 18′ for formingthe supporting members 18 is applied by a spin coat (for 30 seconds atthe rate of 600 rpm) onto the substrate 1 provided with the first pixelelectrode 9 and the black matrix 5 thereon, a pre-baking is conducted(for 3 minutes at 80° C. on a hot plate).

(4) As shown in FIG. 37(d) an ultraviolet (UV) ray of 100 mJ/cm² isirradiated from the substrate 1 side. As a result, with the first pixelelectrode 9 and the black matrix 5 as a mask, the negative type resist18′ on the opening portions 9 a, 5 a, and 5 b is exclusively exposed. Tobe more specific, a back side exposure (self alignment) is conducted toexclusively expose the region where the supporting members 18 areformed, so as to harden the negative type resist 18′ as a result ofpolymerization.

(5) The negative type resist 18′ is developed with a developing solutionand then baked (for 1 hour at 120° C.). As a result, the supportingmembers 18 are formed as high as 4 μm in the regions for the openingportions 9 a, 5 a, and 5 b as shown in FIG. 38(e).

(6) As shown in FIG. 38(f) after a separate layer 26 is formed on thesurface of the transfer member 27 made of an ultraviolet-permeable glasshaving a fixed mask pattern 27 a, the sealing plate 11 is formed (InFIG. 38(f) the surface having the sealing plate 11 is drawn downward).

The mask pattern 27 a is formed in positions corresponding to the drainelectrodes 3 d and 4 d of the TFT devices 3 and 4 so as to shield thelight. To be more specific, the formation of the separate layer 26 canbe conducted by applying a 10 wt % aqueous solution of polyvinyl alcohol(hereinafter referred to as PVA) by spin coat (for 30 seconds at therate of 2000 rpm) and drying it for 2 minutes on a hot plate of 110° C.The sealing plate 11 is formed by applying a negative type resist ontothe separate layer 26 by a spin coat (for 30 minutes at the rate of 2000rpm) and conducting a pre-baking.

(7) As shown in FIG. 39(g) the transfer member 27 is combined with thesubstrate 1 so as to bond the sealing plate 11 to the supportingmaterials 18. In the combination, mask alignment is so conducted thatthe mask pattern 27 a of the transfer member 27 corresponds to the drainelectrodes 3 d and 4 d of the TFT devices 3 and 4, so as to form a 4 μmgap between the substrate 1 and the sealing plate 11.

(8) A mixture solution 21′ is prepared by mixing guest host liquidcrystal and a polymer precursor in a ratio of 80 wt %:20 wt %. The guesthost liquid crystal comprises fluoric nematic liquid crystal and adichroic dye of cyan dissolved therein and the polymer precursorcontains a 3 wt % photopolymerization initiator. The mixture solution21′ is implanted into the gap between the substrate 1 and the sealingplate 11, and a UV ray of 500 mJ/cm² is irradiated from the transfermember 27 side as shown in FIG. 39(h).

As a result of the irradiation of the UV ray, the negative type resistof the sealing plate 11 is polymerized in the region except the drainelectrodes 3 d and 4 d of the TFT devices 3 and 4 shielded by the maskpattern 27 a of the transfer member 27, and the polymer precursor in themixture solution 21′ implanted into the gap is also polymerized, so asto form the liquid crystal layer 21, which is a polymer diffusion typeliquid crystal where the guest host liquid crystal is diffused andretained in polymer network. The sealing plate 11 is fixed on thesubstrate 1 by the polymer network composing the liquid crystal layer21.

(9) As shown in FIG. 40(i) when the substrate 1 is soaked in hot water,the separate layer 26 is dissolved so as to separate the sealing plate11 from the transfer member 27. As a result, the first display layer 6comprising the liquid crystal layer 21 sealed between the substrate 1and the transferred sealing plate 11 is formed.

(10) By developing the sealing plate 11 with a developing solution of anegative type resist, the part of the sealing plate 11 corresponding tothe region above the drain electrodes 3 d and 4 d of the TFT devices 3and 4 which is not exposed due to the mask pattern 27 a during theirradiation of the UV ray in the process (8) is eliminated so as to formthe opening portions 11 a as shown in FIG. 40(j). Furthermore, the partof the liquid crystal layer 21 above the drain electrodes 3 d and 4 d ofthe TFT devices 3 and 4 is not exposed to the UV ray, so that thepolymer precursor is prevented from being polymerized, which fails toform a polymer diffusion type liquid crystal. As a result, the part ofthe liquid crystal layer 21 is easily washed out with the developingsolution of the sealing plate 11 and the opening portions 21 a areformed.

(11) As shown in FIG. 41(k) an ITO transparent conductive film is formedby spattering onto the sealing plate 11 and patterned into the form ofpixel by photolithography and etching so as to form the second pixelelectrode 14. The second pixel electrode 14 is connected with the drainelectrode 3 d of the TFT device 3 via the transparent conductive filmformed in the opening portions 11 a of the sealing plate 11 and on theside walls of the supporting members 18, so that the voltage of thesecond pixel electrode 14 is controlled by the TFT device 3. In order tofacilitate the formation of the transparent conductive film onto theside walls of the supporting members 18, so-called heat drips may beslightly caused in the supporting members 18 by a post-baking so as tomake the supporting members 18 tapered.

(12) The second display layer 7 is formed basically in the same manneras the processes (3)-(11). To be more specific, after the supportingmembers 19 are formed as shown in FIG. 42(l), the liquid crystal layer22, the sealing plate 12, and the third pixel electrode 15 are formed asshown in FIG. 42(m). The formation process of the second display layer 7differs from that of the first display layer 6 only in the followingaspects. The guest host liquid crystal contained in the liquid crystallayer 22 has a dichroic dye of magenta in place of cyan. Furthermore,the mask pattern of the transfer member to form the sealing plate 12masks only the region above the drain electrode 4 d of the TFT device 4so as to form only the opening portions 12 a and 22 a in the supportingmembers 19 and the liquid crystal layer 22.

The formation of the supporting members 19 is conducted by irradiating aUV ray from the substrate 1 side, using the first pixel electrode 9 andthe black matrix 5 as a mask in the same manner as the process (4) offorming the supporting members 18 in the first display layer 6. Thesupporting members 19 are arranged in the exact same position as thesupporting members 18. Since no separate mask is used, mask alignment isunnecessary and the inconvenience shown in FIG. 81 is never caused.

When the above-mentioned UV exposure is conducted, the UV ray isirradiated via the supporting members 18. If the supporting members 18absorb too much UV ray, the negative type resist which form thesupporting members 19 does not have enough irradiation to be fullypolymerized. This causes some of the supporting members 19 to be shorterin height, which makes the liquid crystal layer 22 uneven in thickness,and as a result, the color balance of the liquid crystal display deviceis lost. In such a case, the height of the supporting members 19 can befixed by using a negative type resist having different UV-absorption(exposure) wavelength characteristics from the supporting members 18 asthe negative type resist which composes the supporting members 19, andalso using a UV ray having a wavelength which penetrates the supportingmembers 18 but is heavily absorbed in the negative type resist whichcomposes the supporting members 19. It is also possible to use anegative type resist whose UV-absorption wavelength characteristicschange before and after polymerization, and to irradiate a UV ray havinga wavelength having a high permittivity of the supporting members 18polymerized and having a low permittivity of the negative type resistwhich composes the supporting members 19 not polymerized yet.

(13) As shown in FIGS. 43(n) and 43(o) the third display layer 8 isformed by forming the supporting members 20, the liquid crystal layer23, and the sealing plate 13. The common electrode 16 is formed onto thesealing plate 13. The guest host liquid crystal containing a dichroicdye of yellow is used for the liquid crystal layer 23. Without forming amask pattern on the transfer member for the sealing plate 12, a UV rayis irradiated upon the entire surface of the sealing plate 13, and noopening portion is formed in the sealing plate 13 or the liquid crystallayer 23.

In the third display layer 8, similar to the supporting members 19 ofthe second display layer 7, the supporting members 20 are arranged inthe exact same position as the supporting members 18 and 19 by theirradiation of a UV ray from the substrate 1 side with the first pixelelectrode 9 and the black matrix 5 as a mask. It is preferable to use anegative type resist having different UV absorption (exposure)wavelength characteristics from the supporting members 18 and 19 as thenegative type resist which composes the supporting members 20, and toirradiate a UV ray whose wavelength has high permittivity of thesupporting members 18 and 19.

(14) The protection film 17 made of a transparent acrylic resin isformed onto the common electrode 16 so as to obtain the liquid crystaldisplay device shown in FIGS. 34 and 35.

As mentioned before, the supporting members 18-20 of the display layers6-8 are formed by the rear surface exposure via the opening portions 9a, 5 a, and 5 b of the first pixel electrode 9 and the black matrix 5.This prevents the supporting members 18-20 from being arranged indifferent positions which might lead to the breakage of the firstdisplay layer 6 and other components, so that the cross section of thesupporting members 18-20 can be reduced to 7 μm×7 μm, and the contrastratio can be increased with a larger open area ratio. In addition, nomask alignment is necessary because no mask is used.

Although the supporting members 18-20 each have a square cross sectionand are arranged at regular intervals in these embodiments, the sameeffects can be obtained when the members have other shapes andarrangement. It is also possible that instead of making all thesupporting members 18 have the same shape of cross section, thesupporting members 18 arranged in the region of the first pixelelectrode 9 may have smaller cross section than those in the otherregion.

Although the liquid crystal layers 21-23 are a so-called polymerdiffusion type, liquid crystal containing no polymer network can be usedinstead. This is because liquid crystal can be sealed with the sealingplates 11-13, so that it is not always necessary to use liquid crystalcontaining polymer network. In that case, the liquid crystal makes up alarger proportion of the display layers 6-8, so that the contrast ratiois further increased.

However, the sealing plates 11-13 have no polymer network which servesto fix them on the substrate 1, so that it is necessary to use anadhesive agent or the like.

For this, an adhesive agent can be applied onto either the sealingplates 11-13 or the supporting members 18-20 so as to combine them. Tobe more specific, a thermosetting epoxy resin is applied as the adhesiveagent onto the top of each of the supporting members 18-20, and themembers 18-20 are combined with the sealing plates 11-13. Later, theyare heated in an oven to harden the epoxy resin so as to be bonded. Asthe adhesive agent, a two-part reactive adhesive or other agents may beused.

It is possible to make either the supporting members 18-20 or thesealing plates 11-13 from a plastic material, and to heat or presstogether so as to plasticize either the supporting members 18-20 or thesealing plates 11-13, thereby depositing one onto the other. Forexample, the sealing plates 11-13 composed of a thermoplastic resist arecombined with the supporting members 18-20 and heated in an oven whilebeing pressed, so that the plasticized sealing plates 11-13 aredeposited to the supporting members 18-20.

In the above-mentioned embodiments each of the liquid crystal layers21-23 is formed every time each of the display layers 6-8 is formed;however, when liquid crystal containing no polymer network is used, theliquid crystal layers 21-23 may be formed in the corresponding gapsafter the formation of the supporting members 18-20 and the sealingplates 11-13. The liquid crystal layers can be formed in the same mannereven when liquid crystal contains polymer network; however, in order tofacilitate the formation of the polymer network, it is preferable to usepolymer precursors having different photosensitive wavelengthcharacteristics as described about the supporting members 18-20.

In place of forming the sealing plates 11-13 onto the transfer member 27before transferring them, it is possible to apply a material havingsublimation like camphor as high as the supporting members 18-20 afterthe formation of the supporting members 18-20 so as to form the sealingplates 11-13 thereon. The application of camphor enables the sealingplates 11-13 in the form of thin film to be easily formed thereonto.Also, camphor with sublimation can be removed by being sublimated afterthe formation of the sealing plates 11-13, so that gaps can be easilyformed between the substrate 1 and the sealing plate 11 and between thesealing plates 11-13. It is possible to replace the material havingsublimation by a material vaporized by the irradiation of a UV ray orheating such as a positive type resist made by adding a 1 wt % triphenylsulphonium hexafluoroantimony (Ph3 S+−SbF6) which is onium salt topolyphtalaldehyde (PPA) and dissolving them in cyclohexanone.

Embodiment 3-2

The liquid crystal display device of Embodiment 3-2 will be described asfollows based on FIGS. 44-50.

FIG. 44 is a partial plane view showing the structure of one pixel inthe liquid crystal display device, FIG. 45 is a cross sectional viewtaken along the line indicated with arrows VL—VL of FIG. 44, and FIGS.46-50 are illustrations showing the fabrication processes of the liquidcrystal display device.

In the present embodiment, components having the same structure as thoseof Embodiment 3-1 are referred to with the same reference numbers andtheir description will be omitted.

The liquid crystal display device of the present embodiment resembles tothat of Embodiment 3-1 in that a first pixel electrode provided withopening portions is formed, and the supporting members are formed by theirradiation of a UV ray via the opening portions. The liquid crystaldisplay devices are different in the following aspects. In Embodiment3-1, the liquid crystal layers 21-23 are formed by forming thesupporting members 18-20 onto the substrate 1 by the irradiation of a UVray before bonding the sealing plates 11-13 to the supporting members18-20. In the present embodiment, on the other hand, the mixturesolutions 41′-43′ containing the liquid crystal and the polymerprecursor are sealed after the sealing plates 11-13 are applied. Then, aUV ray is irradiated upon the mixture solutions 41′-43′ so as toprecipitate and harden the polymer precursor (photopolymerizablepolymer) in the mixture solution 41′-43′ for the formation of supportingmembers 31-33 and liquid crystal layers 41-43. Unlike the liquid crystallayers 21-23 in Embodiment 3-1, the liquid crystal layers 41-43 arecomposed of guest host liquid crystal containing no polymer network.

The structure of the liquid crystal display device will be described asfollows based on FIGS. 44 and 45.

In the region of the opening portions 9 a and 5 a of the first pixelelectrode 9 and the black matrix 5 of the liquid crystal display device,4 μm-high supporting members 31-33 are formed as a result of the polymerprecursor mixed with the liquid crystal being polymerized and hardened,instead of the supporting members 18-20 of Embodiment 3-1. On the TFTdevices 3 and 4 and the black matrix 5 close to them, cubicinterconnection pads 28-30 made of the same negative type resist as thesupporting members 18-20 of Embodiment 3-1 are formed as 4 μm-highsupplementary supporting members (the outline of the cubicinterconnection pad 28 is drawn in bold lines in FIG. 44).

The cubic interconnection pad 28 in the first display layer 6 isprovided with opening portions 28 a for cubic interconnection above thedrain electrodes 3 d and 4 d of the TFT devices 3 and 4. The cubicinterconnection pad 29 in the second display layer 7 is provided withopening portions 29 a for cubic interconnection only above the drainelectrodes 4 d of the TFT device 4. The cubic interconnection pad 30 inthe third display layer 8 is provided with no opening portion.

Guest host liquid crystals each containing a dichroic dye of cyan,magenta, and yellow are sealed between the substrate 1 and the sealingplate 11 and between each of the sealing plates 11-13, thereby formingthe liquid crystal layers 41-43. This structure makes the ratio of theliquid crystal to each of the display layers 6-8 larger than in the casewhere the polymer diffusion type liquid crystal layers 21-23 are used asin Embodiment 3-1, so that a higher contrast ratio can be obtained.

The method for fabricating the above-mentioned liquid crystal displaydevice will be described as follows based on FIGS. 46-50.

(1) In the same manner as the process (1) of Embodiment 3-1, the TFTdevices 2-4 and the first pixel electrode 9 having the opening portions9 a are formed onto the substrate 1 made of borosilicate glass as shownin FIG. 46(a).

(2) In the same manner as the process (2) of Embodiment 3-1, the blackmatrix 5 provided with the opening portions 5 a and 5 b are formed asshown in FIG. 46(b).

Then, the cubic interconnection pad 28 is formed onto the black matrix 5by the following processes (3) and (4).

(3) As shown in FIG. 47(c) the negative type resist 28′ for forming thecubic interconnection pad 28 is applied by a spin coat (for 30 secondsat the rate of 600 rpm) onto the substrate 1 provided with the firstpixel electrode 9 and the black matrix 5 thereon, and the substrate 1 ispre-baked (for 3 minutes at 80° C. on a hot plate). After this, a masksubstrate 25 with a mask pattern 25 a is covered and a UV ray isirradiated for exposure. The mask pattern 25 a shields the regions ofthe opening portions 28 a and the regions where the cubicinterconnection pad 28 is not formed.

(4) The negative type resist 28′ thus exposed is developed with adeveloping solution and baked in an oven (for 1 hour at 150° C.) so asto form the cubic interconnection pad 28 onto the TFT devices 3 and 4 asshown in FIG. 47(d). The cubic interconnection pad 28 is formed to havea height of 4 μm and a surface of 20 μm×30 μm. Furthermore, openingportions 28 a of 10 μm×10 μm are formed above the drain electrodes 3 dand 4 d of the TFT devices 3 and 4.

(5) In the same manner as the process (6) of Embodiment 3-1, theseparate layer 26 and the sealing plate 11 are formed on the surface ofthe transfer member 27 provided with a mask pattern 27 a which masks thepositions corresponding to the drain electrodes 3 d and 4 d of the TFTdevices 3 and 4 as shown in FIG. 48(e).

(6) As shown in FIG. 48(f), the transfer member 27 and the substrate 1are positioned in such a manner that the mask alignment of the maskpattern 27 a of the transfer member 27 correspond to the drainelectrodes 3 d and 4 d of the TFT devices 3 and 4, and the sealing plate11 is bonded to the cubic interconnection pad 28. As a result, a 4 μmgap is formed between the substrate 1 and the sealing plate 11. Themixture solution 41′ is prepared by mixing guest host liquid crystal anda polymer precursor in a ratio of 95:5 in weight so as to fill the gaptherewith. The guest host liquid crystal contains a dichroic dye ofcyan.

(7) As shown in FIG. 49(g) a UV ray of 500 mJ/cm² is irradiated from thesubstrate 1 side. As a result, the mixture solution 41′ applied on theopening portions 9 a and 5 a are exclusively exposed with the firstpixel electrode 9 and the black matrix 5 as a mask. In other words, arear surface exposure (self alignment) for exclusively exposing theregion where the supporting members 31 are formed is conducted. As aresult of the irradiation of the UV ray, the polymer precursor in themixture solution 41′ sealed into between the substrate 1 and the sealingplate 11 starts to polymerize and decreases its concentration. Then, thepolymer precursor is condensed by the diffusion due to the unevenness ofthe concentration, and hardened as a polymer above the openings 9 a and5 a so as to form the supporting members 31. At the same time, the guesthost liquid crystal left after the polymer precursor is used for theformation of the supporting members 31 is exclusively sealed intobetween the substrate 1 and the sealing plate 11, so as to form theliquid crystal layer 41.

When the ratio of the area for the supporting members 31 to the area ofthe region filled with the mixture solution 41′ is 5%, the polymerprecursor in the mixture solution 41′ is all used to form the supportingmembers 31 by setting the ratio of the guest host liquid crystal to themixture solution 41′ at 95%, so that only the guest host liquid crystalis sealed into between the substrate 1 and the sealing plate 11.

(8) After irradiating a UV ray of 100 mJ/cm² from the transfer member 27side, the substrate 1 is soaked in hot water to separate the sealingplate 11 from the transfer member 27 in the same manner as the process(9) of Embodiment 3-1, and then the sealing plate 11 is developed withthe developing solution of a negative type resist. Consequently, asshown in FIG. 49(h) while the UV ray is being irradiated, the regionabove the drain electrodes 3 d and 4 d which are not exposed because ofthe mask pattern 27 a of the transfer member 27 are eliminated so as toform the opening portions 11 a for cubic interconnection. (9) In thesame manner as the process (11) of Embodiment 3-1, an ITO transparentconductive film is formed by spattering onto the sealing plate 11 asshown in FIG. 50(i), and patterned into the form of pixel byphotolithography and etching so as to form the second pixel electrode14. The second pixel electrode 14 is connected to the drain electrode 3d of the TFT device 3 via the transparent conductive film formed on theside walls of the opening portions 11 a and 28 a of the sealing plate 11and the cubic interconnection pad 28, so that the voltage of the secondpixel electrode 14 is controlled by the TFT device 3.

(10) The processes (3)-(9) are conducted twice so as to form the seconddisplay layer 7 comprising the second pixel electrode 14, the cubicinterconnection pad 29, the supporting members 32, the liquid crystallayer 42, and the sealing plate 12, and the third display layer 8comprising the third pixel electrode 15, the cubic interconnection pad30, the supporting members 33, the liquid crystal layer 43, and thesealing plate 13. Furthermore, the common electrode 16 is formed on thesealing plate 13, and the protection film 17 made of a transparentacrylic resin is formed on the common electrode 16. As a result, theliquid crystal display device shown in FIGS. 44 and 45 is obtained. Theliquid crystal layers 42 and 43 are composed of a guest host liquidcrystal containing a dichroic dye of magenta and yellow, respectively.The sealing plate 12 and the cubic interconnection pad 29 are providedwith the opening portions 12 a and 29 a exclusively above the drainelectrode 4 d of the TFT device 4, and the sealing plate 13 and thecubic interconnection pad 30 are provided with no opening portions.

As described hereinbefore, similar to Embodiment 3-1, by the rearsurface exposure via the opening portions 5 a and 9 a of the first pixelelectrode 9 and the black matrix 5, the supporting members 31-33 of thedisplay layers 6-8 can have a cross section as small as 7 μm×7μm,thereby increasing the open area ratio.

While the weight ratio of the liquid crystal contained in the polymerdiffusion type liquid crystal layers 21-23 is 80% in Embodiment 3-1, thepolymer precursor in the mixture solution 41′ composed of the guest hostliquid crystal and the polymer precursor is consumed for the formationof the supporting members 31-33 and only the guest host liquid crystalis sealed into between the substrate 1 and the sealing plate 11 andbetween the sealing plates 11-13. As a result, the contrast ratio can befurther increased.

The formation of the supporting members 31-33 requires no mask alignmentunlike the case where a mask is used, whereas the formation of the cubicinterconnection pads 28-30 needs the alignment of the mask substrate 25.However,the alignment does not need to be very precise because thesecubic interconnection pads 28-30 which are as large as 20 μm×30 μm inthe pixel surface do not suffer from the inconvenience shown in FIG. 8by a minor positional deviation.

In the same manner as described in Embodiment 3-1, in the presentembodiment, polymerization of the polymer precursors may be stimulatedby using photopolymerization initiators which have different UVabsorption (exposure) wavelength characteristics in the polymerprecursors for forming the supporting members 31-33.

Instead of transferring the sealing plates 11-13 formed onto thetransfer member 27, the sealing plates may be formed by applying a solidor highly viscous mixture solution containing guest host liquid crystaland a polymer precursor onto the substrate and polymerizing only thesurface and its vicinity of the mixture solution as follows. The surfaceof the substrate is made to be in contact with a material whichaccelerates the polymerization of the polymer precursor contained in themixture solution or to be exposed to a UV ray. The material can be amixture solvent of pure water and isopropyl alcohol in a volume ratio of10:1 where a 5 wt % amine-base activating agent of an acrylic resin isdissolved.

Embodiment 3-3

The liquid crystal display device of the present embodiment will bedescribed as follows based on FIGS. 51 through 57.

FIG. 51 is a partial sectional view showing the structure of one pixelin the liquid crystal display device.

FIGS. 52 through 57 are illustrations showing the fabrication processesof the liquid crystal display device.

In the present embodiment, components having the same structure as thoseof Embodiments 3-1 and 3-2 are referred to with the same referencenumbers and their description will be omitted.

The liquid crystal display device of the present embodiment comprisesthe supporting members 18-20 formed by polymerizing and hardening anegative type resist as in Embodiment 3-1, and the supporting members31-33 formed by polymerizing and hardening the polymer precursor mixedwith liquid crystal in the same manner as in Embodiment 3-2. As shown inFIG. 51, the supporting members 18 alternate with the supporting members31, the supporting members 19 alternate with the supporting members 32,and the supporting members 20 alternate with the supporting members 33.It is the same feature as in Embodiments 3-1 and 3-2 that the supportingmembers 18-20 and 31-33 are formed by the exposure of a UV ray via theopening portions 9 a, 5 a, and 5 b of the first pixel electrode 9 andthe black matrix 5. The liquid crystal layers 41-43 are exclusivelycomposed of the guest host liquid crystal left unconsumed after thepolymer precursor is used for the formation of the supporting members31-33. The structure of the liquid crystal display device of the presentembodiment is equal to that of Embodiment 3-1 except the supportingmembers 31-33 and the liquid crystal layers 41-43.

The method for fabricating the liquid crystal display device will bedescribed as follows based on FIGS. 52 through 57.

(1) As shown in FIG. 52(a) the TFT devices 2-4 and the first pixelelectrode 9 provided with the opening portions 9 a are formed onto thesubstrate 1 made of borosilicate glass in the same manner as the process(1) of Embodiment 3-1.

(2) As shown in FIG. 52(b) the black matrix 5 provided with the openingportions 5 a and 5 b is formed in the same manner as the process (2) ofEmbodiment 3-1.

Through the following processes (3)-(5), the supporting members 18 halfas many as those of Embodiment 3-1 are formed.

(3) As shown in FIG. 53(c) the negative type resist 18′ for forming thesupporting members 18 is applied onto the substrate 1 and pre-baked inthe same manner as the process (3) in Embodiment 3-1.

(4) As shown in FIG. 53(d) a mask substrate 34 provided with a maskpattern 34 a which shields the opening portions 9 a″ and 5 a″ of theopening portions 9 a and 5 a in the first pixel electrode 9 and theblack matrix 5 is arranged outside the substrate 1, and a UV ray isirradiated from the substrate 1 side so as to polymerize and harden thenegative type resist 18′ in the region for the opening portions 9 a′, 5a′, and 5 b.

(5) The negative type resist 18′ is developed with a developing solutionand baked in the same manner as the process (5) of Embodiment 3-1, so asto form the supporting members 18 on the opening portions 9 a′, 5 a′,and 5 b as shown in FIG. 54(e).

(6) As shown in FIG. 54(f) the separate layer 26 and the sealing plate11 are formed on the surface of the transfer member 27 provided with themask pattern 27 a for mask alignment corresponding to the drainelectrodes 3 d and 4 d of the TFT devices 3 and 4 in the same manner asthe process (6) of Embodiment 3-1.

(7) As shown in FIG. 55(g) the transfer member 27 and the substrate 1are combined in such a manner that the sealing plate 11 is bonded to thesupporting members 18, and the mixture solution 41′ composed of apolymer precursor and guest host liquid crystal containing a dichroicdye of cyan is implanted in a gap between the substrate 1 and thesealing plate 11 in the same manner as the process (6) of Embodiment3-2.

(8) As shown in FIG. 55(h) a UV ray of 500 mJ/cm² is irradiated from thesubstrate 1 side, and the polymer precursor contained in the mixturesolution 41′ is polymerized in the opening portions 9 a″ and 5 a″ wherethe supporting members 18 are not formed in the processes (4) and(5). Asa result, the supporting members 31 and the liquid crystal layer 41 areformed.

The ratio of the polymer precursor to the remaining components in themixture solution 41′ is made equal to the ratio of the area for thesupporting members 31 to the area of the region where the mixturesolution 41′ (except for the region where the supporting members 18 ofthe negative type resist are previously formed) is sealed into. Thismakes all the polymer precursor be used for the formation of thesupporting members 31 so that only the guest host liquid crystal issealed into between the substrate 1 and the sealing plate 11. As aresult, the substantial open area ratio can be increased in the samemanner as in Embodiment 3-2.

(9) As shown in FIG. 56(i) after a UV ray is irradiated from thetransfer member 27 side, the substrate 1 is soaked in hot water in orderto separate the sealing plate 11 from the transfer substrate 27. Afterthis, the sealing plate 11 is developed with a developing solution of anegative type resist, and the opening portions 11 a for cubicinterconnection are formed as shown in FIG. 57(j) in the same manner asthe process (8) of Embodiment 3-2.

(10) As shown in FIG. 57(k), an ITO transparent conductive film isformed by spattering onto the sealing plate 11 and patterned into theform of pixel by photolithography and etching so as to form the secondpixel electrode 14 in the same manner as the process (11) of Embodiment3-1.

(11) The processes of (3)-(10) are conducted twice so as to form thesecond display layer 7 comprising the second pixel electrode 14, thesupporting members 19 and 32, the liquid crystal layer 42, and thesealing plate 12, and the third display layer 8 comprising the thirdpixel electrode 15, the supporting members 20 and 33, the liquid crystallayer 43, and the sealing plate 13. Furthermore, the common electrode 16is formed on the sealing plate 13, and the protection film 17 made of atransparent acrylic resin is formed on the common electrode 16. As aresult, the liquid crystal display device shown in FIG. 51 is obtained.

As described hereinbefore, the gap between the substrate 1 and thesealing plate 11 and the gaps between each of the sealing plates 11-13are kept at a fixed thickness by the supporting members 18-20 so thatthe display colors of the liquid crystal display device are wellbalanced in the same manner as in Embodiment 3-1. Furthermore, thesubstantial open area ratio is increased so as to further increase thecontrast ratio in the same manner as Embodiment 3-2.

The alternate arrangement of the supporting members 18-20 made of thenegative type resist and the supporting members 31-33 made of a polymercan make each of the gaps between the substrate 1 and the sealing plate11 and between the sealing plates 11-13 have a fixed thickness and thepolymer precursor be condensed more efficiently; however, the ratio intheir numbers and the arrangement are not limited to these.

Embodiment 3-4

The liquid crystal display device of the present embodiment will bedescribed as follows based on FIGS. 58 through 64. FIG. 58 is a partialplane view showing the structure of one pixel in the liquid crystaldisplay device, FIG. 59 is a cross sectional view taken along the lineindicated with arrows LIX—LIX of FIG. 58, and FIGS. 60-64 areillustrations showing the fabrication processes of the liquid crystaldisplay device.

In the present embodiment, components having the same structure as thosein Embodiments 3-1, 3-2, and 3-3 are referred to with the same referencenumbers and their description will be omitted.

The liquid crystal display device of the present embodiment differs fromthose in Embodiments 3-1, 3-2, and 3-3 mainly in that the supportingmembers 61-63 are formed by polymerizing and hardening a positive typeresist instead of a negative type resist. Therefore, the substrate 1 isprovided with a light shielding film 35 in the positions where thesupporting members 61-63 are formed. Instead of the TFT devices 2-4, theTFT devices 82-84 having drain electrodes 82 d-84 d made of atransparent conductive film are provided.

The structure of the liquid crystal display device will be described asfollows based on FIGS. 58 and 59.

The first pixel electrode 36 and the drain electrodes 82 d-84 d of theTFT devices 82-84 are ITO transparent conductive films. The otherelectrodes including the gate electrode 82 b in the TFT devices 82-84are equal to those of the TFT device 2-4. The light shielding film 35 isprovided in the positions corresponding to the opening portions 9 a and5 a of the first pixel electrode 9 and the black matrix 5 of Embodiment3-1 in the first pixel electrode 36 and its vicinity and on the TFTdevices 83 and 84 and their vicinities. The light shielding film 35 hasopening portions 35 b in the regions of the drain electrodes 83 d and 84d of the TFT devices 83 and 84 (In FIG. 58 the regions where the lightshielding film 35 is formed are shown with dots).

The light shielding film 35 is made of a black resist containing carbonparticles, which is the same material as the black matrix 5 used inEmbodiment 3-1. Instead, the film 35 may be a metallic thin film made ofaluminum or the like by conducting photolithography and etching.

The light shielding film 35 is provided with supporting members 61-63made by hardening a positive type resist and the cubic interconnectionpads 71-73 thereon. The cubic interconnection pad 71 is provided withopening portions 71 a for cubic interconnection above the drainelectrodes 83 d and 84 d of the TFT devices 83 and 84. The cubicinterconnection pad 72 is provided with opening portions 72 a only abovethe drain electrode 84 d of the TFT device 84.

In place of the common electrode 16 made of a transparent conductivefilm used in Embodiments 3-1, 3-2, and 3-3, a common electrode 39 madeof a reflective film is provided on the sealing plate 13 of the thirddisplay layer 8. Furthermore, a protection film 17 the same as those ofEmbodiments 3-1, 3-2, and 3-3 is formed on the common electrode 39. Theprotection film 17 does not have to be transparent.

In the liquid crystal display device thus structured, the light(external light) incident from the substrate 1 side penetrates thesubstrate 1, the first-third display layers 6, 7, and 8 in that order,is reflected by the common electrode 39, and goes back through thethird-first display layers 8, 7, and 6, and the substrate 1 in thatorder, so as to conduct display. The display screen is seen from thesubstrate 1 side.

The method for fabricating the liquid crystal display device will bedescribed as follows based on FIGS. 60-63.

(1) As shown in FIG. 60(a) after the region other than the drainelectrodes 82 d-84 d of the TFT devices 82-84 are formed onto thesubstrate 1, an ITO transparent conductive film is formed by spatteringand patterned by photolithography and etching so as to form the firstpixel electrode 36 and the drain electrodes 83 d and 84 d. The firstpixel electrode 36 differs from that used in Embodiment 3-1 in that itis a transparent conductive film and have no opening portions, and isequal in that it also serves as the drain electrode 82 d of the TFTdevice 82.

(2) A black resist containing carbon particles is applied as thick as 0.5 μm onto the substrate 1, and then mask exposure and development areconducted in a manner that the resist is left only on the spots wherethe supporting members 61-63 and the cubic interconnection pads 71-73are provided in a later process. As a result, the light shielding film35 is formed as shown in FIG. 60(b).

Through the following processes (3)-(5), the supporting members 61 andthe cubic interconnection pad 71 are formed.

(3) As shown in FIG. 61(c), the positive type resist 61′ for forming thesupporting members 61 and the cubic interconnection pad 71 is applied bya spin coat (for 30 seconds at the rate of 600 rpm) onto the substrate 1provided with the first pixel electrode 36 and the light shielding film35 thereon. After that, the substrate 1 is pre-baked (for 3 minutes at80° C. on a hot plate).

(4) As shown in FIG. 61(d) a UV ray of 100 mJ/cm² is irradiated from thesubstrate 1 side. Thus, the positive type resist 61′ on the region wherethe light shielding film 35 is not formed is exclusively exposed withthe light shielding film 35 as a mask.

(5) After being developed with a developing solution, the positive typeresist 61′ is baked (for 1 hour at 120° C.), so as to form thesupporting members 61 and the cubic interconnection pad 71 onto thelight shielding film 35 as shown in FIG. 62(e). Since the drainelectrodes 83 d and 84 d of the TFT devices 83 and 84 are transparentconductive films, the opening portions 71 a are formed above the drainelectrodes 83 d and 84 d in the cubic interconnection pad 71. The cubicinterconnection pad 71, which has the same shape as the cubicinterconnection pad 28 used in Embodiment 3-2 is formed in the sameprocess as the supporting members 61 by rear surface exposure.

The first display layer 6 is formed in the same manner as in Embodiment3-1 as follows.

(6) As shown in FIG. 62(f) the separate layer 26 and the sealing plate11 are formed on the surface of the transfer member 27 in the samemanner as the process (6) of Embodiment 3-1.

(7) As shown in FIG. 63(g) the transfer member 27 and the substrate 1are combined in the same manner as the process (7) of Embodiment 3-1.

(8) As shown in FIG. 63(h) the mixture solution 21′ composed of theguest host liquid crystal and the polymer precursor is implanted intothe gap between the substrate 1 and the sealing plate 11, and a UV rayof 500 mJ/cm² is irradiated from the transfer member 27 side. As aresult, the liquid crystal layer 21 of a polymer diffusion type liquidcrystal is formed in the same manner as the process (8) of Embodiment3-1.

(9) After the substrate 1 is soaked in hot water in order to separatethe sealing plate 11 from the transfer member 27, the sealing plate 11is developed with a developing solution of a negative type resist so asto form the opening portions 11 a as shown in FIG. 64(i) in the samemanner as the process (9) of Embodiment 3-1.

(10) As shown in FIG. 64(j) the ITO transparent conductive film isformed by spattering onto the sealing plate 11 and patterned into theform of pixel by photolithography and etching so as to form the secondpixel electrode 14 in the same manner as the process (11) of Embodiment3-1.

(11) The processes of (3)-(10) are conducted twice so as to form thesecond display layer 7 comprising the second pixel electrode 14, thecubic interconnection pad 72, the supporting members 62, the liquidcrystal layer 22, and the sealing plate 12, and the third display layer8 comprising the third pixel electrode 15, the cubic interconnection pad73, the supporting members 63, the liquid crystal layer 23, and thesealing plate 13. Furthermore, the common electrode 36 which also servesas a reflective film is formed on the sealing plate 13 of the thirddisplay layer 8 by depositing aluminum as thick as 2000 Å. Also, theprotection film 17 for protecting the liquid crystal display device fromexternal pressure and the like is formed onto the common electrode 39,so as to obtain the liquid crystal display device shown in FIGS. 58 and59.

As a result of the supporting members 61-63 of the first display layers6-8 being formed by the rear surface exposure with the light shieldingfilm 35 using a positive type resist as described above, no positionaldeviation is caused among the supporting members 61-63 which mightdamage the first display layer 6 and the other components. Consequently,mask alignment becomes unnecessary and the size of the supportingmembers 61-63 is reduced so as to increase the open area ratio, therebyincreasing the contrast ratio.

Although the liquid crystal display device in the present embodiment isreflective type, a permeable type liquid crystal display device can beconstructed by making the common electrode 39 of a transparentconductive film.

Although the liquid crystal display device comprises polymer diffusiontype liquid crystal layers 21-23, liquid crystal containing no polymernetwork may be used as explained in Embodiment 3-1.

The method of forming the sealing plates 11-13 onto the transfer member27 and transferring them can be replaced by the following method. Afterthe supporting members 18-20 are formed, the sealing plates 11-13 may beformed on a material which is applied as thick as the supporting members18-20 by being vaporized by the irradiation of a UV ray or heating suchas a positive type resist made by adding a 1 wt % triphenyl sulphoniumhexafluoroantimony (Ph3 S+−SbF6) which is onium salt topolyphtalaldehyde (PPA) and dissolving them in cyclohexanone. Since thematerial enables the sealing plates 11-13 in the form of thin film to beeasily formed thereon and can be vaporized by the irradiation of a UVray or heating, the material can be removed by evaporation after thesealing plates 11-13 are formed, which facilitates the formation of thegap between the substrate 1 and the sealing plate 11.

Fourth Embodiment

Embodiment 4-1

The present embodiment will be described as follows based on FIGS. 65through 74. In order to simplify the description, components unrelatedto the description are omitted and some components are drawn inmagnified or reduced sizes.

FIG. 65 is a cross sectional view showing the rough structure of theliquid crystal display device of the present embodiment.

As shown in FIG. 65 the liquid crystal display device comprises an arraysubstrate 301, a display unit 303, and anisotropic conductive adhesivematerials (first to third connection means) 302 a-302 c whichelectrically connect the array substrate 301 and the display unit 303.

The array substrate 301 comprises a glass substrate 311, TFT devices(first to third nonlinear elements) 312-314, and driving electrodes(first to third driving electrodes) 315-317.

As shown in FIG. 66 the TFT devices 312-314 are electrically connectedwith the driving electrodes 315-317, respectively, which are connectedwith the drain side terminals of the TFT devices 312-314, respectively.The pitch Q of the TFT devices 312-314 in X direction is about 100 μmwhen the pixel pitch P=300 μm, and the pitch R in Y direction is about300 μm. The driving electrodes 315-317, which have a maximum width S of80 μm and a length T of 250 μm are made of ITO and arranged in one pixelin the form of stripe like the stripe arrangement of an RGB pixel in acolor filter.

As shown in FIG. 67 the display unit 303 comprises a substrate 321, apolymer resin layer 322, and the first-third display layers 323-325having three liquid crystal layers filled with guest host liquidcrystals of different colors arranged between the substrate 321 and thepolymer resin layer 322.

The substrate 321 is made of glass and provided with a common electrode329 thereon. The substrate 321 can be made of a polymer resin such asplastic instead of glass. The common electrode 329 is an ITO electrodeand connected with a ground of the array substrate 301 with a conductivepaste (not shown) made of a resin containing carbon power applied in thevicinity of the display region.

The first display layer 323 comprises a first liquid crystal layer 326,a first pixel electrode 330, a first sealing plate 333, and spacers(first supporting members) 341 a. To be more specific, spacers 341 a arearranged at regular intervals on the common electrode 329 and a firstsealing plate 333 is provided on the spacers 341 a. Furthermore, a firstpixel electrode 330 patterned in a fixed form is provided on the firstsealing plate 333.

As shown in FIG. 67 a second display layer 324 and a third display layer325 which have almost the same structure as the first display layer 323are formed in that order onto the first display layer 323. To be morespecific, the second display layer 324 comprises a second liquid crystallayer 327, a second pixel electrode 331, a second sealing plate 334, andspacers (second supporting members) 341 b, whereas the third displaylayer 325 comprises a third liquid crystal layer 328, a third pixelelectrode 332, a third sealing plate 335, and spacers (third supportingmembers) 341 c.

The first-third display layers 323-325 are each provided with cubicinterconnection pads 342 and 342′ (refer to FIG. 67) which are providedwith opening portions 342 a and 342′a, respectively. Furthermore, thesecond and third sealing plates 334 and 335 are provided with contactholes 343, and the polymer resin layer 322 is provided with contactholes 344. Consequently, the first pixel electrode 330 is electricallyconnected with a connection terminal 354 via the opening portion 342 aof the cubic interconnection pad 342 and a relay electrode 351 providedin the contact holes 343 and 344. The second pixel electrode 331 iselectrically connected with a connection terminal 355 via the openingportion 342′a of the cubic interconnection pad 342′ and the relayelectrode 351. The third pixel electrode 332 is electrically connectedwith a connection terminal 356 via the contact holes 344.

The first-third liquid crystal layers 326-328 are filled with guest hostliquid crystals. To be more specific, the guest host liquid crystals arechiral nematic liquid crystal made of a mixture in which a dichroic dyeof cyan, magenta, or yellow as a guest and a chiral agent for making a 7μm helical pitch are added to a positive type nematic liquid crystal asa host.

As shown in FIG. 69 the first and second pixel electrodes 330 and 331are made of a transparent ITO film. The first pixel electrode 330 isconnected with the TFT device 314 via the relay electrode 351 and theconnection terminal 354 so as to be used for both the first and secondliquid crystal layers 326 and 327. To be more specific, the first pixelelectrode 330 is used as a pixel electrode for the first liquid crystallayer 326 and as a counter electrode for the second liqliquid crystallayer 327. Similarly, the second pixel electrode 331 is used as a pixelelectrode for the second liquid crystal layer 327 and as a counterelectrode for the third liquid crystal layer 328. The third pixelelectrode 332, which is made of aluminum with a thickness of 500 nm hasa function as a reflective film.

The first-third sealing plates 333-335 are made of a polymer compoundfilm, and their thickness is set at 1.0 μm in the present embodiment.

The spacers 341 a-341 c are 4 μm-high square pillars whose cross sectionis about 10 μm×10 μm and are arranged regularly with a 50 μm pitch onthe first-third display layers 323-325, respectively. The shape andarrangement not only prevent each of the first-third liquid crystallayers 326-328 from becoming uneven in thickness due to the bending ofthe first-third sealing plates 333-335, but also secure a 95% or highereffective open area ratio. Also, the structure has excellent mechanicalstrength. The area density (size and arrangement pitch) of the spacers341 a-341 c is not limited to the one mentioned above, but can be set inaccordance with the material and thickness of the first-third sealingplates 333-335 so as to secure the stacking of the first-third liquidcrystal layers 326-328 and the effective open area ratio.

The cubic interconnection pads 342 and 342′ are 4 μm-high square pillarswhose cross section is about 30 μm×30 μm and are provided with openingportions 342 a and 342′a (diameter: 10 μm) for cubic interconnection,respectively.

As shown in FIG. 66 the connection terminals 354-356 are made ofaluminum in the form of rectangle with a width U of 50 μm and a length Vof 150 μm. The pitch between these connection terminals is 100 μm.

As shown in FIG. 70 the anisotropic conductive adhesive materials 302are adhesive beads made by coating 5 μm-diameter beads 71 (made of anacrylic resin) plated with gold 373 with an epoxy resin 372. Theanisotropic conductive adhesive materials 302 are diffused so as to makea dispersion density at least as high as to connect the array substrate301 and the display unit 303 electrically on the array substrate 301. Tobe more specific, the anisotropic conductive adhesive materials 302a-302 c are pressed so that the driving electrodes 315-317 are connectedwith the connection terminals 354-356, respectively, via a bead 371. Asa result, as shown in FIG. 70(b) the epoxy resin 372 becomes an oval,which prevents the short circuit with an adjacent one of the anisotropicconductive adhesive materials 302.

The method for fabricating the liquid crystal display device of thepresent embodiment will be described as follows.

As shown in FIG. 71(a) the transparent common electrode 329 made of ITOis formed onto the substrate 321. After forming a light shielding film361 made of chrome onto the regions corresponding to the spacers 341 aand the cubic interconnection pads 342 and 342′, a positive type resist(OFPR800 produced by Tokyo Ohka Kogyo Co., Ltd.) is applied as thick as4.0 μm by using a spinner or the like. Furthermore, by the exposure fromthe substrate 321 side and the following development, the spacers 341 aand the cubic interconnection pads 342 and 342′ are formed as shown inFIG. 71(b).

Then, a 1.0 μm-thick negative type resist film on which a 0.2 μm-thickadhesive layer made of an urethane resin is applied is laminated ontothe spacers 341 a and the cubic interconnection pads 342 and 342′. Thenegative type resist is bonded onto the spacers 341 a, and a UV ray isirradiated from the negative type resist side. As a result, the negativetype resist is polymerized and hardened so as to form the first sealingplate 333 as shown in FIG. 72(a). Although the first sealing plate 333is bonded onto the substrate 321 in the vicinity of the display regionhaving no spacers 341 a, that is, in the non-display region, spacers areprovided in part of the non-display region so as to provide the inletsof the liquid crystal.

An ITO film is formed onto the first sealing plate 333 by spattering,and patterned to form the first pixel electrode 330 by photolithographyand etching.

The guest host liquid crystal prepared by dissolving a cyan dichroic dyein a positive type chiral nematic liquid crystal is implanted throughthe inlets and the inlets are closed, so as to form the first liquidcrystal layer 326 as shown in FIG. 72(a).

The second liquid crystal layer 327 is produced in the same manner asthe first liquid crystal layer 326. The positive type resist is appliedonto the first pixel electrode 330, exposed from the substrate 321 side,so as to form the spacers 341 b and the cubic interconnection pads 342and 342′ on the same positions as those of the first liquid crystallayer 326 in a self-aligned manner.

A negative type resist film on which an adhesive layer is applied islaminated onto the spacers 341 b and the cubic interconnection pads 342and 342′. As shown in FIG. 72(b) a UV ray is irradiated in accordancewith a normal mask exposure while shielding the spot in the center ofthe cubic interconnection pad 342 where the 10 micron-diameter openingportion 342 a is to be formed. The opening portion 342 a is formed inthe resist film, and the other region is hardened by development so asto form the second sealing plate 334. Although the second sealing plate334 is bonded onto the substrate 321 in the vicinity of the displayregion having no spacers 341 b, spacers are provided in part of thenon-display region so as to provide the inlets of the liquid crystal.

An ITO film is formed on the second sealing plate 334 by spattering, andthe second pixel electrode 331 and the relay electrode 351 are formed byphotolithography and etching. A guest host liquid crystal comprising apositive type chiral nematic liquid crystal and a dichroic dye ofmagenta dissolved therein is implanted through the inlets so as to formthe second liquid crystal layer 327 as shown in FIG. 73(a).

The third liquid crystal layer 328 is formed in the same manner as thesecond liquid crystal layer 327 as follows. The spacers 341 c and thecubic interconnection pads 342 and 342′ are formed in a self-alignedmanner onto the second pixel electrode 331. A negative type resist filmwith an adhesive layer applied thereon is laminated onto the spacers 341c and the cubic interconnection pads 342 and 342′.

A UV ray is irradiated in accordance with a normal mask exposure whileshielding the spots where the opening portions 342 a and 342′a of thecubic interconnection pads 342 and 342′ are to be formed. The openingportions 342 a and 342′a are formed in the negative type resist film andthe other region is hardened so as to form the third sealing plate 335.Although the third sealing plate 335 is bonded onto the substrate 321 inthe vicinity of the display region having no spacers 341, spacers areprovided in part of the non-display region so as to provide the inletsof the liquid crystal.

An aluminum film is formed as thick as 500 nm onto the third sealingplate 335 by spattering, and the third pixel electrode 332 and the relayelectrode 351 are formed by photolithography and etching. A guest hostliquid crystal comprising a positive type chiral nematic liquid crystaland a dichroic dye of yellow dissolved therein is implanted through theinlets so as to form the third liquid crystal layer 328 as shown in FIG.73(b).

Furthermore, a 5 μm-thick negative type resist (FVR produced by FujiYakuhin) is applied onto the third sealing plate 335. Then, thepositions where the contact holes 344 are formed are covered with amask, and light is irradiated upon the negative type resist to behardened. As a result, as shown in FIG. 74(a) the polymer resin layer322 having contact holes 344 is formed. The polymer resin layer 322 hashardness corresponding to 4H of pencil hardness by JIS examination. Thehardness prevents the anisotropic conductive adhesive materials 302 fromsinking into the third sealing plate 335 and making its surface unevenwhen the array substrate 301 and the display unit 303 are bonded to eachother via the anisotropic conductive adhesive materials 302.

Then, a 500 nm-thick aluminum film is formed onto the polymer resinlayer by spattering, and patterned to have a fixed shape. Consequently,the connection terminals 354-356 are formed as shown in FIG. 74(b).

The inspection process for inspecting the display conditions of thedisplay unit 3 is conducted as follows. With an inspector, theconnection terminals 354-356 are supplied with voltage to drive thefirst-third liquid crystal layers 326-328. While no voltage is beingapplied, the first-third liquid crystal layers 326-328 exhibit lights ofcyan, magenta, and yellow, respectively, and while a voltage is beingapplied, these layers become transparent, making it possible to inspecttheir operational conditions. When an error such as point defect or linedefect is detected in the display unit 303, only the display unit 303 isabandoned. Since the inspection process is conducted before the arraysubstrate 301 and the display unit 303 are combined, it becomesunnecessary to abandon the array substrate 301 together with the displayunit 303 when the display unit 303 is detected to be defective. As aresult, the fabrication cost is decreased and the yield is increased.

The anisotropic conductive adhesive materials 302 are diffused onto theglass substrate 311 previously provided with the TFT devices 312-314 andthe driving electrodes 315-317 which are the drain ends of these TFTdevices. It is preferable that the amount of diffusing the anisotropicconductive adhesive materials 302 is so adjusted as to be distributed atleast one for each of the connection terminals 354-356.

After the connection terminals 354-356 and the driving electrodes315-317 are aligned, the array substrate 301 and the display unit 303are combined. The alignment does not need higher accuracy than arrangingthe array substrate 301 and the display unit 303 with certain precisionon a plane. They are combined by being pressed with 0.2 atmosphericpressure while being heated at 120° C. The application of 0.2atmospheric pressure changes the epoxy resin 372 in the anisotropicconductive adhesive materials 302 to an oval form. As a result, the goldplating 373 is in contact with the driving electrode 315 and theconnection terminal 356 so as to connect them. The epoxy resin 372,which becomes an oval has an insulation function in the directionorthogonal to the film thickness direction.

Since the epoxy resin 372 can be hardened by being heated at 120° C.,the array substrate 301 and the display unit 303 can be combined whilethe connection between the driving electrodes 315-317 and the connectionterminals 354-356 is maintained.

It has been confirmed that when the reflective type liquid crystaldisplay device of the present embodiment thus fabricated is driven byentering image signals and the like to the array substrate 301, brightcolor images are displayed. Since the array substrate 301 and thedisplay unit provided with the first-third liquid crystal layers 326-328are independent of each other, even when a display defect is detected inthe liquid crystal layers, the array substrate 301 having TFT devices312-314 does not have to be abandoned. Consequently, the fabricationcost is decreased and the yield is increased.

In the present embodiment, gold-plated acrylic resin beads 371 arecoated with the epoxy resin 372 to make the anisotropic conductiveadhesive materials 302; however, the adhesive materials may beconductive only in the thickness direction of the liquid crystal displaydevice. Even conductive adhesive materials having no anisotropy in thethickness direction can be used by controlling its dispersion density soas not to cause short circuit between an adjacent pixel and theconductive adhesive materials connected to each other.

Although TFT devices are used as non-linear elements in the presentembodiment, two-terminal elements such as diodes can be used instead.Also a resin substrate provided with a driver IC thereon such as amulti-layered circuit substrate may be used for the array substrate. Inthat case, a further cost reduction can be realized when the liquidcrystal display device has high fabrication cost.

Although the third pixel electrode 332 is used as a reflective film inthe present embodiment, it is possible that the electrode 332 is atransparent electrode and the common electrode made of aluminum or thelike is a reflective film. Also the third pixel electrode 332 can beformed on the surface of the glass substrate 311 or the substrate 321.

The thickness of the first-third sealing plates 333-335 is 1.0 μm in thepresent embodiment; however, it can be in the range of 0.5 to 10 μm.

To be more specific, the thinner the first sealing plate 333 is, thesmaller the voltage to be supplied to the liquid crystal layer 326 canbe, so that the driving voltage of the TFT devices 312-314 can bereduced. However, when the first sealing plate 333 is too thin, it isdeformed during the formation of the first pixel electrode 330, causingwrinkles or cracks. Consequently, the first sealing plate 333 ispreferably 0.5 μm or thicker. On the other hand, when the first sealingplate 333 is too thick, the dispersion density of the spacers 341 can bereduced, but there is a problem that the voltage to be supplied to thefirst liquid crystal layer 326 is decreased. Consequently, it ispreferable that the first sealing plate 333 is 10 μm or thinner.

Embodiment 4-2

The present embodiment will be described as follows based on FIGS. 75and 76. In the present embodiment, components having the same structureas those of Embodiment 4-1 are referred to with the same referencenumbers and their description will be omitted.

Embodiment 4-1 shows a reflective type liquid crystal display devicehaving three liquid crystal layers sequentially stacked. In contrast,the present embodiment shows a liquid crystal display device having asingle liquid crystal layer.

FIG. 75 is a cross sectional view showing the structure of the liquidcrystal display device of the present embodiment.

The liquid crystal display device comprises a display unit 391, adriving substrate 392, and an adhesive material 393 which bonds thedisplay unit 391 and the driving substrate 392.

The drive substrate 392 is provided with the pixel electrodes 386 madeof aluminum or the like arranged with a fixed pitch on the surface of aresin interconnection substrate 387 which faces the display unit 391,and further provided with a peripheral circuit composed of various LSIsor a driver circuit 390 on the outside. The resin interconnectionsubstrate 387 is made of a glass epoxy resin and has a through hole 388to connect the pixel electrodes 386 and the driver circuit 390electrically.

The display unit 391 is composed of a plastic substrate 381 and adisplay layer 389 formed thereon. A transparent electrode 383 made of anITO film is formed on the entire surface of the plastic film substrate381. A 100 μm-thick polarizing plate 382 made of polyethylene vinylalcohol is provided outside the plastic substrate 381.

The display layer 389 is composed of spacers 395, a sealing plate 384,and a liquid crystal layer 385. The sealing plate 384 is 1 μm-thick PET(Polyethilene Telephthalate) film. The PET film is stretched to be athin film and has birefringence of about 0.05 μm. The liquid crystallayer 385 consists of a chiral nematic liquid crystal containing achiral agent so as to make a 32 μm helical pitch. Consequently, theliquid crystal molecules in the vicinity of the sealing plate 384 arehomogeneously aligned which is the direction of stretching the film, andthe liquid crystal layer 385 has twist nematic alignment with a twist of45 degrees. The liquid crystal layer 385 has a gap of 4 μm.

The adhesive material 393 is a 1 μm-thick urethane resin. Besidesurethane resin, it can be made of any of various well-known adhesiveagents.

The method for fabricating the liquid crystal display device of thepresent embodiment will be described as follows.

First, the transparent electrode 383 made of an ITO film is formed byspattering onto the entire surface of the plastic film substrate 381provided with a polarizing plate 382 made of polyethylene vinyl alcohol.After forming a light shielding film 361 made of chrome on the spotscorresponding to the spacers 395 in the same manner as Embodiment 4-1, aresist film is applied as thick as 4.0 μm. Exposure is conduced from theplastic film substrate 381 side followed by development so as to formthe spacers 395.

Then, a 1.0 μm-thick PET film is prepared by stretching a polymer resinmaterial made of PET. A 0.2 μm-thick adhesive layer made of an urethaneresin is applied onto the PET film and laminated onto the spacers 395 byheat press with a roll 394 shown in FIG. 76. As a result, the PET filmis bonded onto the spacers 395 so as to form the sealing plate 384. Inthe vicinity of the display region not provided with the spacers 395,that is, in the non-display region, the sealing plate 384 is bonded ontothe plastic film substrate 381; however, the spacers 395 are provided inpart of the non-display region in order to provide the inlets of theliquid crystal.

The chiral nematic liquid crystal having a helical pitch of 32 μm isimplanted through the inlets, so as to form the liquid crystal layer385.

An adhesive material 352 made of an urethane resin is applied on thesurface of the sealing plate 384 where the liquid crystal layer 385 isnot formed.

On the other hand, an aluminum film is formed onto the resininterconnection substrate 387 by spattering and patterned to have afixed shape, so as to form the pixel electrode 386. Furthermore, adriver circuit 390 is mounted outside the resin interconnectionsubstrate 387.

The display unit 391 and the driving substrate 392 are bonded to eachother by disposing the adhesive material 393 therebetween and applyingheat press using a heated roll. As a result, the reflective type liquidcrystal display device of the present embodiment is completed.

As described hereinbefore, unlike Embodiment 4-1, the reflective typeliquid crystal display device of the present embodiment has the liquidcrystal layer 385 between the common electrode 383 and the sealing plate384, and the pixel electrode 386 not on the sealing plate 384 but on theresin interconnection substrate 387. Therefore, the reflective typeliquid crystal display device does not require to produce the displayunit 391 in accordance with the pattern of the pixel electrode 386 onthe driving substrate 392, so that the display pattern which is varieddepending on the uses can be easily produced only by changing theformation pattern of the pixel electrode 386 on the resininterconnection substrate 387 side.

In other words, the display layer can correspond to various arraysubstrates having different display patterns depending on the uses,which contributes to a cost reduction.

When the display unit 391 and the driving substrate 392 are combined,their relative position on a plane is arbitrary, so that no alignment isrequired, which facilitates the assembly. Since the display unit 391 isformed in close contact with the resin interconnection substrate 387made of a glass epoxy resin, it is not very affected by bending, whichmakes it possible to use a very thin plastic film substrate for thedisplay unit 391. As a result, an extremely thin and light reflectivetype liquid crystal display device is obtained which comprises plasticliquid crystal using a plastic film substrate and being integrated intothe resin interconnection substrate 387. The resin interconnectionsubstrate 387 has various peripheral circuits mounted thereon in orderto realize various functions including image display, as describedabove. Therefore, to mount the pixel electrode 386 or the driver circuit390 onto the resin interconnection substrate 387 itself does notcontribute to a cost increase.

Although the thickness of the sealing plate 384 is 1.0 μm in the presentembodiment, it can be in the range of 0.5 to 10 μm. To be more specific,the thinner the sealing plate 384 is, the larger the voltage to besupplied to the liquid crystal layer 385 can be, which can reduce thedriving voltage. However, when the sealing plate 384 is too thin, it isdeformed during the formation of the pixel electrode 386, causingwrinkles or cracks. Consequently, the sealing plate 384 is preferably0.5 μm or thicker.

On the other hand, when the sealing plate 384 is too thick, thedispersion density of the spacers 395 can be reduced, but there is aproblem that the voltage to be supplied to the liquid crystal layer 385is decreased. Consequently, the thickness of the sealing plate 384 ispreferably 10 μm or below because when the thickness is similar to thegap of the liquid crystal layer 385, the liquid crystal layer 385 can bedriven with a comparatively low voltage without providing a pixelelectrode on the sealing plate 384.

Embodiment 4-3

The present embodiment will be described as follows based on FIGS. 77and 78. In the present embodiment, components having the same structureas those of Embodiments 4-1 and 4-2 are referred to with the samereference numbers and their description will be omitted.

The liquid crystal display device of the present embodiment is amulti-screen LCD composing a large screen display where liquid crystalpanels having 600×800×trio (×3) pixels with a pitch of 330 μm arearranged. To be more specific, as shown in FIGS. 77(a) and 77(b) theliquid crystal display device comprises a display unit 501, an arraysubstrate 502, and an adhesive material 407 which bonds the display unit501 and the array substrate 502.

The adhesive material 407 is a transparent acrylic thermosettingadhesive material containing no solvent. As shown in FIG. 77(a) thedisplay unit 501 comprises a liquid crystal layer 403 between thesubstrate 410 and the sealing plate 384,which is supported by thespacers 409. The substrate 410 is provided with a polarizing plate 405on its external surface, and with a color filter layer 401 on itsinternal surface. The color filter layer 401 is provided with a commonelectrode 329 thereon and an alignment film 402 is formed on the commonelectrode 329. A total of 120×1600×3 rectangular pixel electrodes 404are arranged on the sealing plate 384 in the form of matrix at intervalsof 110 μm.

The substrate 410 is made from glass of a rectangle whose diagonallength is 85 cm. The liquid crystal layer 403 has a structure wherechiral nematic liquid crystal having a helical pitch of 50 μm is twisted90 degrees to form a twisted nematic alignment. The alignment film ismade of a polyimide resin.

The spacers 409 are 5.0 μm-high square pillars whose cross section isabout 10 μm×10 μm and are arranged regularly with a 50 μm pitch on thecommon electrode 309. The shape and arrangement not only prevent theliquid crystal layer 403 from becoming uneven in thickness due to thehanging down of the sealing plate 384 but also secure an about 95%effective open area ratio. The area density (size and arrangement pitch)of the spacers 409 is not limited to the one mentioned above, but can beset in accordance with the material and thickness of the sealing plate384 so as to secure the stacking of the liquid crystal layer 403 and theeffective open area ratio.

The color filter layer 401 has a structure where the sub pixels of red,green, and blue are arranged in the form of stripe with a 110 82 mpitch.

The array substrate 502 is composed of four array substrates 502 a-502d. The array substrate 502 a is composed of a glass substrate 311 aprovided with TFT devices 312 whose semiconductor layers are made ofamorphous silicon. The TFT devices 312 are arranged in the form ofmatrix with a pitch of 330 μm. Aluminum terminals 408 having a height of500 nm in their thickness direction are provided on the drain electrode(not shown) side of each of the TFT devices 312. A housing unit 411 forforming the driving circuit 413 is provided in the periphery of theright crossing two sides of the array substrate 502 a. The arraysubstrates 502 b-502 d have almost the same structure as the arraysubstrate 502 a.

The method for fabricating the liquid crystal display device of thepresent embodiment will be described as follows.

The common electrode 329 is formed by spattering onto the substrate 410previously provided with the color filter layer 401. The polyimide resinis applied onto the common electrode 329, and subjected to a rubbingmethod in a fixed direction so as to form the alignment film 402.

In the same manner as Embodiment 4-2, after the light shielding filmmade of chrome is formed on the spots corresponding to the spacers 409,a positive type resist is applied as thick as 5.0 μm using a spinner.Then, exposure is conducted from the substrate 410 side followed bydevelopment so as to form the spacers 409.

The 1.0 μm-thick PET film on which a 0.2 μm-thick adhesive layer made ofan urethane resin is applied is subjected to a lamination treatment soas to form the sealing plate 384. The PET film is thinned by previouslybeing stretched in the direction orthogonal to the rubbing directionwhen the rubbing method is conducted to form the alignment film 402. Asa result, the liquid crystal molecules in the vicinity of the sealingplate 384 are oriented in the direction parallel to the stretchingdirection, and the liquid crystal molecules in the vicinity of thealignment film 402 are oriented in the direction parallel to the rubbingdirection, so as to form a twisted nematic alignment with a twist of 90degrees.

In the vicinity of the display region not provided with the spacers 409,the sealing plate 384 is bonded onto the substrate 410; however, somespacers 409 are arranged in part of the non-display region in order toprovide the inlets of the liquid crystal.

An ITO film is formed on the sealing plate 384, and photolithography andetching are conducted to form the pixel electrodes 404. Furthermore,chiral nematic liquid crystal is implanted through the inlets so as toform the liquid crystal layer 403.

The TFT devices 312 are formed on the glass substrate in a conventionalmanner. The aluminum terminals 408 are formed on the drain electrodeside of each of the TFT devices 312. The glass substrate is divided intothe array substrates 502 a-502 d with a scriber so that the arraysubstrates 502 a-502 d each have a housing unit 411 for mounting adriving circuit along the right crossing two sides of the arraysubstrate. There is an error of about 30 μm between the measures setbefore dividing the substrate and the measures obtained after thesubstrate is actually divided, which makes the array substrate 502 aslightly closer to the center than the array substrate 502 b. As shownin FIG. 78 the array substrates 502 a-502 d are arranged so as to placethe housing units 411 outward and fixed with an enclosure 412.

An adhesive material 407 is applied on the sealing plate 384 and thepixel electrode 404 in the display unit 501. The display unit 402 andthe array substrates 502 a-502 d fixed within the enclosure 412 arealigned, and heated while a fixed pressure is being applied so as toharden the adhesive material 407. The alignment does not need higheraccuracy than arranging the array substrates 502 a-502 d and the displayunit 501 with a fixed precision on a plane.

The polarizing plate 405 is arranged outside the substrate 410 and apolarizing plate 406 is arranged outside the array substrates 311 a-311d. Finally, a back light is provided outside the glass substrate 311. Asa result, the permeable type liquid crystal display device of thepresent embodiment is obtained.

As described hereinbefore, the permeable type liquid crystal displaydevice of the present embodiment has an effect of enabling continuousimage display in a large screen without showing the joints among thearray substrates 502 a-502 d on the screen, in addition to the sameeffect as that of Embodiment 4-1.

To be more specific, a conventional multi-screen LCD is composed of aplurality of liquid crystal panels each having a unit for providing adriving circuit at the edges of the display region. Arranging theseliquid crystal panels generates spaces between the display regions ofadjacent liquid crystal panels, making the pitch of the pixel electrodesuneven at the joints among the liquid crystal panels. As a result,images become intermittent on the display screen, making jointsrecognizable. In conventional devices, various improvements are tried inorder to make the joints unnoticeable. For example, the pixel pitch ismade large or the panels are arranged so precisely as to make thedifference in precision between the measures set before dividing theliquid crystal panel and the measures obtained after the liquid crystalpanel is actually divided. However, it is still difficult to arrange theliquid crystal panels so precisely as to make the joints unnoticeablebecause the division of the panels is conducted mechanically.

In contrast, in the permeable type liquid crystal display device of thepresent embodiment, the pixel electrodes 404 are arranged in the displayunit 501 with a fixed pixel pitch, and not provided in the arraysubstrates 502 a-502 d, so that the pitch does not become uneven. As aresult, the image displayed on the screen does not become discontinuous.Also precise alignment is unnecessary when the array substrates 502a-502 d are arranged on the same plane. Since the pixel pitch does nothave to be larger, high precision can be obtained. Thus, unlike theconventional multi-screen LCD, the present embodiment can provide aliquid crystal display device capable of offering continuous images in alarge screen without showing the joints among the panels.

Although the present invention has bee fully described by way ofexamples with reference to the accompanying drawings, it is to be notedthat various changes and modifications will be apparent to those skilledin the art. Therefore, unless such changes and modifications depart fromthe scope of the resent invention, they should be construed as beingincluded therein.

INDUSTRIAL UTILIZATION

As described hereinbefore, the structure of the present invention canachieve all the objects of the present invention.

To be more specific, the liquid crystal display device is structure byforming gaps between a substrate and a resin film and between eachadjacent resin films, and then sealing liquid crystal into the gaps. Inthis structure, the liquid crystal display device does not causeunevenness in color resulting from the parallax due to the stacking ofliquid crystal layers, so that bright display and a high contrast ratioare realized. Also the fabrication processes are simplified and thefabrication yield is increased.

The liquid crystal display device comprising stacked resin films makesit possible to connect the electrodes formed on these resin films byconducting a contact hole formation process only one time, securing theconnection inside contact holes. The use of an inorganic material suchas ITO as the transparent electrodes formed on the resin films preventsthe resin films from wrinkling and keeps their surfaces smooth, whichmakes the liquid crystal display device maintain its characteristics asa display device.

The supporting members are formed by exposing a photosensitive resinlayer via the opening portions formed in the reflective film so as toharden the resin layer. This makes it possible to reduce the fabricationcost because a mask alignment process becomes unnecessary in forming thesupporting members and to easily increase the contrast ratio by reducingthe area for the supporting members.

The use of conductive connection means for connecting the display layerhaving the liquid crystal layers and the array substrate havingnon-linear elements makes it possible to provide a full-color liquidcrystal display device which is fabricated at a low cost with a higheryield because it does not need to abandon the array substrate when aliquid crystal layer or the like has a display defect. The liquidcrystal display device has another effect of lowering the precisionlevel in alignment because the pixel electrodes and the drivingelectrodes may be relatively positioned in a plane only to be connectedeach other by the connection means.

The use of an adhesive material for combining the driving substratehaving the pixel electrodes and the driving circuits, and the displaylayer having the liquid crystal layers and the common electrode makes itunnecessary to produce the display layer in accordance with the patternform of the driving electrodes on the driving substrate. Therefore, thedisplay layer can correspond to various array substrates havingdifferent display patterns depending on the uses. Since the displaylayer and the driving substrate can be combined in an arbitrary relativeposition on a plane, no alignment is required, which facilitates theassembly. It is also possible to provide a liquid crystal display devicewhich is thin and light in weight and defies bending or otherdeformation, and a method for fabricating the liquid crystal displaydevice.

The use of an adhesive material to bond the display layer provided withpixel electrodes arranged at regular intervals and a plurality of arraysubstrates provided with non-linear elements prevents the joints amongthe array substrates from becoming recognizable on the display screen.Thus, it becomes possible to provide a liquid crystal display devicehaving a multi-screen where the joints among the panels areunnoticeable, and a method for fabricating the liquid crystal displaydevice.

What is claimed is:
 1. A liquid crystal display device comprising: asubstrate having a pixel electrode and a driving element connected tothe pixel electrode on a surface of said substrate; a resin film beingdisposed above said substrate and having a common electrode on a surfaceof said resin film; a plurality of supporting members each beingcolumnar and standing on said substrate so as to support said resinfilm; an adhesive layer being disposed between said resin film and saidplurality of supporting members so as to bond said resin film to saidplurality of supporting members, said adhesive layer being made of athermoplastic material and exerting thermoplastic characteristics so asto bond said resin film to said plurality of supporting members; and aliquid crystal layer being composed of liquid crystal and being disposedbetween said substrate and said resin film.
 2. The liquid crystaldisplay device of claim 1, wherein said resin film is made of one of amaterial having no thermoplasticity and a material havingthermoplasticity and exerting thermoplastic characteristics at a highertemperature than said adhesive layer; and said plurality of supportingmembers are made of one of a material having no thermoplasticity, amaterial having thermoplasticity and exerting thermoplasticcharacteristics at a higher temperature than said adhesive layer, and amaterial being hardened before said resin film is bonded to saidplurality of supporting members.
 3. The liquid crystal display device ofclaim 1, wherein said substrate is a transparent substrate; and saidplurality of supporting members and said adhesive layer are a positivetype photo resist formed by disposing a light shielding film over spotson said substrate where said plurality of supporting members arearranged and by conducting photolithography using the light shieldingfilm as a photo mask.
 4. The liquid crystal display device of claim 1,wherein said substrate is a transparent substrate; and said plurality ofsupporting members and said adhesive layer are a negative type photoresist formed by disposing a light shielding film on said substrateexcluding spots where said plurality of supporting members are arrangedand by conducting photolithography using the light shielding film as aphoto mask.
 5. The liquid crystal display device of claim 1, wherein adistance between adjacent ones of said plurality of supporting membersarranged in a pixel region, of said plurality of supporting members isin a range of 15 to 100 μm.
 6. The liquid crystal display device ofclaim 1, wherein thickness of said resin film is in a range of 0.5 to 10μm.
 7. The liquid crystal display device of claim 1, wherein resistivityof said resin film is 10¹⁰ Ω·cm or below.
 8. The liquid crystal displaydevice of claim 1, wherein said resin film has breathability, and saidcommon electrode is made of a metallic material having reflectioncharacteristics and also serves as a shading film for preventing oxygenor moisture in open air from permeating through said resin film.
 9. Theliquid crystal display device of claim 1, wherein said resin film hasbreathability, and a shading film is provided on said common electrodeso as to prevent oxygen or moisture in open air from permeating throughsaid resin film.
 10. The liquid crystal display device of claim 9,wherein said common electrode is a transparent electrode, and saidshading film is made of a metallic material having reflectioncharacteristics and also serves as a reflective plate.
 11. The liquidcrystal display device of claim 1, wherein said common electrode is atransparent electrode; a resin layer is formed on said common electrode,said resin layer being transparent and having a multiplicity of fineconvex and concave portions on a surface thereof; and a reflective filmhaving a shape of a multiplicity of fine convex and concave portions isformed correspondingly on said multiplicity of fine convex and concaveportions on the surface of said resin layer.
 12. A liquid crystaldisplay device comprising: a substrate being transparent and having apixel electrode and a driving element connected to the pixel electrodeon a surface of said substrate; a plurality of resin films being stackedabove said substrate, an uppermost resin film of said plurality of resinfilms having a common electrode on a surface thereof, and remaining onesof said plurality of resin films each having a pixel electrode on asurface thereof; a plurality of liquid crystal layers each being formedby arranging a plurality of supporting members each being columnar ineach gap between said substrate and a lowermost resin film of saidplurality of resin films and between adjacent ones of said plurality ofresin films, and by sealing liquid crystal into said each gap; saidsubstrate having more driving elements on the surface thereof, said moredriving elements being electrically connected to a corresponding one ofthe pixel electrodes formed on the remaining ones of said plurality ofresin films via cubic interconnection provided in relation to each ofthe pixel electrodes formed on the remaining ones of said plurality ofresin films; a plurality of adhesive layers each being disposed betweeneach of said plurality of supporting members and each of said pluralityof resin films, said plurality of adhesive layers being made of athermoplastic material and exerting thermoplastic characteristics so asto bond each of said plurality of resin films to each of said pluralityof supporting members; and the supporting members between adjacent onesof said plurality of resin films being arranged substantially in samepositions as the supporting members between said substrate and thelowermost resin film with respect to a plane parallel to said substrate.13. The liquid crystal display device of claim 12, wherein saidplurality of resin films are made of one of a material having nothermoplasticity and a material having thermoplasticity and exertingthermoplastic characteristics at a higher temperature than saidplurality of adhesive layers; and said plurality of supporting membersare made of one of a material having no thermoplasticity, a materialhaving thermoplasticity and exerting thermoplastic characteristics at ahigher temperature than said plurality of adhesive layers, and amaterial being hardened before said plurality of resin films are bondedto said plurality of supporting members.
 14. The liquid crystal displaydevice of claim 12, wherein three liquid crystal layers and three resinfilms are stacked, and the liquid crystals composing the three liquidcrystal layers are guest host liquid crystals each containing a dichroicdye, each dichroic dye having a different color from remaining dichroicdyes.
 15. The liquid crystal display device of claim 14, wherein thethree resin films have optical anisotropy and are so arranged as to makeall slow axes of the three resin films be in a same direction.
 16. Theliquid crystal display device of claim 12, wherein said substrate is atransparent substrate; and said plurality of supporting members and saidplurality of adhesive layers are a positive type photo resist formed bydisposing a light shielding film over spots on said substrate where saidplurality of supporting members are arranged and by conductingphotolithography using the light shielding film as a photo mask.
 17. Theliquid crystal display device of claim 12, wherein said substrate is atransparent substrate; and said plurality of supporting members and saidplurality of adhesive layers are a negative type photo resist formed bydisposing a light shielding film on said substrate excluding spots wheresaid plurality of supporting members are arranged and by conductingphotolithography using the light shielding film as a photo mask.
 18. Theliquid crystal display device of claim 12, wherein a distance betweenadjacent ones of said plurality of supporting members arranged in apixel region, of said plurality of supporting members is in a range of15 to 100 μm.
 19. The liquid crystal display device of claim 12, whereinthickness of said plurality of resin films is in a range of 0.5 to 10μm.
 20. The liquid crystal display device of claim 12, whereinresistivity of said plurality of resin films is 10¹⁰ Ω·cm or below. 21.The liquid crystal display device of claim 12, wherein said plurality ofresin films have optical anisotropy and are so arranged as to make allslow axes said plurality of resin films be in a same direction.
 22. Theliquid crystal display device of claim 12, wherein said plurality ofresin films have breathability, and said common electrode is made of ametallic material having reflection characteristics and also serves as ashading film for preventing oxygen or moisture in open air frompermeating through the uppermost resin film.
 23. The liquid crystaldisplay device of claim 12, wherein said plurality of resin films havebreathability, and a shading film is provided on said common electrodeso as to prevent oxygen or moisture in open air from permeating throughthe uppermost resin film.
 24. The liquid crystal display device of claim23, wherein said common electrode is a transparent electrode, and saidshading film is made of a metallic material having reflectioncharacteristics and also serves as a reflective plate.
 25. The liquidcrystal display device of claim 12, wherein said common electrode is atransparent electrode; a resin layer is formed on said common electrode,said resin layer being transparent and having a multiplicity of fineconvex and concave portions on a surface thereof; and a reflective filmhaving a shape of a multiplicity of fine convex and concave portions isformed correspondingly on said multiplicity of fine convex and concaveportions on the surface of said resin layer.
 26. A method forfabricating a liquid crystal display device comprising the steps of:arranging a plurality of supporting members each being columnar onto asubstrate, said substrate being transparent and having a pixel electrodeand a driving element connected with the pixel electrode thereon;forming an adhesive layer onto said plurality of supporting members;bonding a resin film to said plurality of supporting members bydisposing said resin film onto said adhesive layer formed on saidplurality of supporting members and applying heat to said resin filmwhile maintaining a gap between said substrate and said resin film;forming a common electrode onto a surface of said resin film; andsealing liquid crystal into said gap between said substrate and saidresin film.
 27. The method for fabricating a liquid crystal displaydevice of claim 26, wherein the step of bonding said resin to saidplurality of supporting members comprises the sub step of pressing saidresin film with a heated roller.
 28. The method for fabricating a liquidcrystal display device of claim 27, wherein said adhesive layer is madeof a material which exerts thermoplastic characteristics at a lowertemperature than said resin film exerting thermoplastic characteristics,and the heated roller heats said resin film to a temperature lower thansaid resin film exerting thermoplastic characteristics and higher thansaid adhesive layer exerting thermoplastic characteristics.
 29. Themethod for fabricating a liquid crystal display device of claim 27,wherein at least a surface of the heated roller is made of a rigidmaterial.
 30. The method for fabricating a liquid crystal display deviceof claim 26, wherein the step of arranging said plurality of supportingmembers onto said substrate comprises: forming a light shielding filmover spots on a surface of said substrate where said plurality ofsupporting members are arranged; applying a first positive type resistonto the surface of said substrate; exposing the first positive typeresist from a rear surface of said substrate using the light shieldingfilm as a photo mask; and developing the first positive type resist witha first developing solution and hardening the first positive typeresist; and the step of forming said adhesive layer onto said pluralityof supporting members comprises: applying a second positive type resistonto the surface of said substrate having said plurality of supportingmembers thereon; exposing the second positive type resist from the rearsurface of said substrate using the light shielding film as the photomask; and developing the second positive type resist with a seconddeveloping solution.
 31. The method for fabricating a liquid crystaldisplay device of claim 26, wherein the step of forming an adhesivelayer and the step of bonding said resin film comprises: preparing saidresin film applied with an adhesive layer; and arranging said resin filmonto said plurality of supporting members with heating so that saidsurface applied with said adhesive layer faces said plurality ofsupporting members.
 32. The method for fabricating a liquid crystaldisplay device of claim 26, wherein in the step of arranging saidplurality of supporting members on said substrate, supporting membersarranged in a pixel region are formed to have more width than height.33. The method for fabricating a liquid crystal display device of claim26, wherein thickness of said resin film is in a range of 0.5 to 10 μm.34. The method for fabricating a liquid crystal display device of claim26, wherein a main component of said resin film is a polyester resin.35. The method for fabricating a liquid crystal display device of claim26, wherein in the step of bonding said resin film to said plurality ofsupporting members, a venthole is formed in order to ventilate said gapbetween said substrate and said resin film.
 36. The method forfabricating a liquid crystal display device of claim 35, wherein saidventhole is formed by leaving a part of said substrate without beingbonded to said resin film, said part being in a vicinity of a displayportion on said substrate.
 37. The method for fabricating a liquidcrystal display device of claim 36, wherein an internal wall of saidventhole is subjected to a treatment for decreasing a surface tension.38. The method for fabricating a liquid crystal display device of claim35, wherein said venthole is formed by bonding said resin film to saidsubstrate in a vicinity of a display portion on said substrate so as toonce seal said gap, and forming a through hole in a region outside adisplay portion of said resin film.
 39. The method for fabricating aliquid crystal display device of claim 35 further comprising the step ofclosing said venthole.
 40. A method for fabricating a liquid crystaldisplay device comprising the steps of: arranging a plurality of firstsupporting members on a substrate, said substrate being transparent andhaving a pixel electrode and a driving element connected to the pixelelectrode thereon; forming a first adhesive layer onto said pluralityfirst of supporting members; bonding a first resin film to saidplurality of first supporting members by disposing the first resin filmonto the first adhesive layer formed on said plurality of firstsupporting members and applying heat to the first resin film whilemaintaining a gap between said substrate and the first resin film;forming a first opening portion in the first resin film; forming a firstpixel electrode on the first resin film and electrically connecting thefirst pixel electrode to a corresponding driving element on saidsubstrate via the first opening portion; stacking one other resin filmor more resin films by first stacking a second resin film whilemaintaining a gap between the first resin film and the second resin filmby arranging a plurality of second supporting members on the first resinfilm bonded to said plurality of first supporting members; forming asecond adhesive layer onto said plurality of second supporting members;bonding the second resin film to said plurality of second supportingmembers; forming a second opening portion in the second resin film; andforming a second pixel electrode on the second resin film andelectrically connecting the second pixel electrode to a correspondingdriving element formed on said substrate via the second opening portion;forming a plurality of uppermost supporting members on a resin film laststacked in a previous stacking step and disposing an uppermost adhesivelayer onto said plurality of uppermost supporting members so as to bondan uppermost resin film to said plurality of uppermost supportingmembers; forming a common electrode on a surface of the uppermost resinfilm; and sealing liquid crystal into said gap between said substrateand the first resin film and said gap between adjacent resin films. 41.The method for fabricating a liquid crystal display device of claim 40,wherein each opening portion is formed by reactive ion etching.
 42. Themethod for fabricating a liquid crystal display device of claim 40,wherein the step of bonding the first resin to said plurality of firstsupporting members comprises the sub step of pressing said resin filmwith a heated roller; and the step of stacking one other resin film ormore resin films comprises the sub step of pressing each resin film witha heated roller.
 43. The method for fabricating a liquid crystal displaydevice of claim 42, wherein each adhesive layer is made of a materialwhich exerts thermoplastic characteristics at a lower temperature thaneach resin film exerting thermoplastic characteristics, and the heatedroller heats said each resin film to a temperature lower than said eachresin film exerting thermoplastic characteristics and higher than saideach adhesive layer exerting thermoplastic characteristics.
 44. Themethod for fabricating a liquid crystal display device of claim 42,wherein at least a surface of the heated roller is made of a rigidmaterial.
 45. The method for fabricating a liquid crystal display deviceof claim 40, wherein the step of forming an adhesive layer and the stepof bonding the first resin film to said plurality of first supportingmembers comprise: preparing the first resin film applied with anadhesive layer; and arranging the first resin film onto said pluralityof first supporting members with heating so that said surface appliedwith said adhesive layer faces said plurality of first supportingmembers; and the step of stacking one other resin film or more resinfilms comprises: preparing the second resin film applied with an otheradhesive layer; and arranging the second resin film onto said pluralityof second supporting members with heating so that said surface appliedwith said other adhesive layer faces said plurality of second supportingmembers.
 46. The method for fabricating a liquid crystal display deviceof claim 40, wherein in the step of arranging said plurality of firstsupporting members on said substrate, first supporting members arrangedin a pixel region are formed to have more width than height.
 47. Themethod for fabricating a liquid crystal display device of claim 40,wherein thickness of each resin film is in a range of 0.5 to 10 μm. 48.The method for fabricating a liquid crystal display device of claim 40,wherein a main component of each resin film is a polyester resin. 49.The method for fabricating a liquid crystal display device of claim 40,wherein in the step of bonding the first resin film to said plurality offirst supporting members, a first venthole is formed in order toventilate said gap between said substrate and the first resin film; andin the step of stacking one other resin film or more resin films, asecond venthole is formed in order to ventilate said gap between thefirst resin film and the second resin film.
 50. The method forfabricating a liquid crystal display device of claim 49, wherein thesecond venthole is formed by leaving a part of the first resin filmwithout being bonded to the second resin film, said part being in avicinity of a display portion on said substrate.
 51. The method forfabricating a liquid crystal display device of claim 50, wherein aninternal wall of the second venthole is subjected to a treatment fordecreasing a surface tension.
 52. The method for fabricating a liquidcrystal display device of claim 49, wherein the first venthole and thesecond venthole are formed by bonding the first resin film to saidsubstrate and bonding the second resin film to the first resin film in avicinity of a display portion on said substrate so as to once seal saidgap between said substrate and the first resin film and said gap betweenthe first resin film and the second resin film, and forming a throughhole in a region outside a display portion of all resin films stacked.53. The method for fabricating a liquid crystal display device of claim49 further comprising the step of closing the first venthole and thesecond venthole.
 54. A liquid crystal display device comprising: asubstrate having a pixel electrode and a driving element connected tothe pixel electrode on a surface of said substrate; a resin film beingdisposed above said substrate; a plurality of supporting members eachbeing columnar and standing on said substrate so as to support saidresin film; an adhesive layer being disposed between said resin film andsaid plurality of supporting members so as to bond said resin film tosaid plurality of supporting members, said adhesive layer being made ofa thermoplastic material and exerting thermoplastic characteristics soas to bond said resin film to said plurality of supporting members; aliquid crystal layer being composed of liquid crystal and being disposedbetween said substrate and said resin film; a resin layer being formedon a surface of said resin film, said resin layer being transparent andhaving a multiplicity of fine convex and concave portions on a surfacethereof; and a reflective film having a shape of a multiplicity of fineconvex and concave portions and being formed correspondingly on saidmultiplicity of fine convex and concave portions on the surface of saidresin layer, said reflective film also serving as a common electrode.55. A liquid crystal display device comprising: a substrate having apixel electrode and a driving element connected to the pixel electrodeon a surface of said substrate; a plurality of resin films being stackedabove said substrate, said plurality of resin films each having a pixelelectrode on a surface thereof except an uppermost resin film of saidplurality of resin films; a plurality of liquid crystal layers eachbeing formed by arranging a plurality of supporting members each beingcolumnar in each gap between said substrate and a lowermost resin filmof said plurality of resin films and between adjacent ones of saidplurality of resin films, and by sealing liquid crystal into said eachgap; said substrate having more driving elements on the surface thereof,said more driving elements being electrically connected to acorresponding one of the pixel electrodes formed on said plurality ofresin films except the uppermost resin film via cubic interconnectionprovided in relation to each of the pixel electrodes formed on saidplurality of resin films except the uppermost resin film; a plurality ofadhesive layers each being disposed between each of said plurality ofsupporting members and each of said plurality of resin films, saidplurality of adhesive layers being made of a thermoplastic material andexerting thermoplastic characteristics so as to bond each of saidplurality of resin films to each of said plurality of supportingmembers; the supporting members between adjacent ones of said pluralityof resin films being arranged substantially in same positions as thesupporting members between said substrate and the lowermost resin filmwith respect to a plane parallel to said substrate; a resin layer beingformed on a surface of the uppermost resin film, said resin layer beingtransparent and having a multiplicity of fine convex and concaveportions on a surface thereof; and a reflective film having a shape of amultiplicity of fine convex and concave portions and being formedcorrespondingly on said multiplicity of fine convex and concave portionson the surface of said resin layer, said reflective film also serving asa common electrode.
 56. A method for fabricating a liquid crystaldisplay device comprising the steps of: arranging a plurality ofsupporting members each being columnar onto a substrate, said substratebeing transparent and having a pixel electrode and a driving elementconnected with the pixel electrode thereon; forming an adhesive layeronto said plurality of supporting members; bonding a resin film to saidplurality of supporting members by disposing said resin film onto saidadhesive layer formed on said plurality of supporting members andapplying heat to said resin film while maintaining a gap between saidsubstrate and said resin film; forming a resin layer whose surface has amultiplicity of fine convex and concave portions by applying a photoresist onto a surface of said resin film, subjecting the surface of saidresin film to mask exposure, developing, and baking; forming areflective film also serving as a common electrode onto the surface ofsaid resin layer; and sealing liquid crystal into said gap between saidsubstrate and said resin film.
 57. A method for fabricating a liquidcrystal display device comprising the steps of: arranging a plurality offirst supporting members each being columnar on a substrate, saidsubstrate being transparent and having a pixel electrode and a drivingelement connected to the pixel electrode thereon; forming a firstadhesive layer onto said plurality of first supporting members; bondinga first resin film to said plurality of first supporting members bydisposing the first resin film onto the first adhesive layer formed onsaid plurality of first supporting members and applying heat to thefirst resin film while maintaining a gap between said substrate and thefirst resin film; forming a first opening portion in the first resinfilm; forming a first pixel electrode on the first resin film andelectrically connecting the first pixel electrode to a correspondingdriving element on said substrate via the first opening portion;stacking one other resin film or more resin films by first stacking asecond resin film while maintaining a gap between the first resin filmand the second resin film by arranging a plurality of second supportingmembers on the first resin film bonded to said plurality of firstsupporting members; forming a second adhesive layer onto said pluralityof second supporting members; bonding the second resin film to saidplurality of second supporting members; forming a second opening portionin the second resin film; and forming a second pixel electrode on thesecond resin film and electrically connecting the second pixel electrodeto a corresponding driving element formed on said substrate via thesecond opening portion; forming a plurality of uppermost supportingmembers on a resin film last stacked in a previous stacking step anddisposing an uppermost adhesive layer onto said plurality of uppermostsupporting members so as to bond an uppermost resin film to saidplurality of uppermost supporting members; forming a resin layer whosesurface has a multiplicity of fine convex and concave portions byapplying a photo resist onto a surface of the uppermost resin film,subjecting the surface of the uppermost resin film to mask exposure,developing, and baking; forming a reflective film also serving as acommon electrode onto the surface of said resin layer; and sealingliquid crystal into said gap between said substrate and the first resinfilm and said gap between adjacent resin films.